- 2x5x2.5mm | MR52
- 2x6x2.5mm | MR62
- 3x6x2.5mm | MF63
- 3x6x2.5mm | MR63
- 3x7x3mm | 683
- 3x8x3mm | MR83
- 3x8x4mm | 693
- 3x10x4mm | 623
- 4x8x3mm | MR84
- 4x8mm Flanged MF84
- 4x7x2.5mm | MR74
- 4x8x3mm | MR84
- 4x9x4mm 684
- 4x10x4mm | MR104
- 4x11x4mm | 694
- 4x13x5mm | 624
- 5x8mm Flanged
- 5x8x2.5mm | MR85
- 5x9x3mm | MR95
- 5x9x3mm Flanged | MF95
- 5x10x3mm
- 5x10x4mm flanged | MF104
- 5x10x4mm | MR105
- 5x11x4mm | MR115
- 5x11x5mm
- 5x12x4mm
- 5x13x4mm
- 5x14x5mm | 605
- 5x16x5mm | 625
- 6x10x3mm | MR106
- 6x10x3mm Flanged | MF106
- 6x12x4mm | MR126
- 6x12x4mm Flanged | MF126
- 6x13x5mm | 686
- 6x15x5mm | 696
- 6x16x5mm
- 6x19x6mm | 626
- 7x11x3mm | MR117
- 7x13x4mm | MR137
- 7x14x5mm | 687
- 7x17x5mm | 697
- 7x19x6mm | 607
- 7x22x7mm | 627
- 8x14mm
- 8x14x4mm | MR148
- 8x14x4mm Flanged | MF148
- 8x16x5mm | 688
- 8x16x5mm Flanged | MF688
- 8x19x6mm | 698
- 8x22x7mm | 608
- 9x17x5mm | 689
- 9x20x6mm | 699
- 10x15x4mm flanged | F6700
- 10x15x4mm | 6700
- 10x16x4mm
- 10x16x5mm | MR1016
- 10x19x5mm | 6800
- 10x22x6mm | 6900
- 10x26x8mm | 6000
- 10x28x8mm | 16100
- 12x18x4mm | 6701
- 12x21x5mm | 6801
- 12x24x6mm | 6901
- 12x28x8mm | 6001
- 13x19x4mm
- 13x20x4mm
- 14x25.4x6mm
- 14x25.8x6mm
- 15x21x4mm | 6702
- 15x24x5mm | 6802
- 15x24x5mm Flanged | F6802
- 15x26x7mm | 15267
- 15x28x7mm | 6902
- 15x32x9mm | 6002
- 17x26x5mm | 6803
- 17x28x7mm | 17287
- 17x30x7mm | 6903
- 17x40x12mm | 6203
- 18x30x7mm | 18307
- 20x27x4mm | 6704
- 20x32x7mm | 6804
- 20x42x12mm | 6004
- 20x47x14mm | 6204
- 24x37x7mm
- 25x37x6mm | 6805-6
- 25x37x7mm | 6805-7
- 25x52x15mm | 6205
- 29x42x7mm | 6806/29
- 30x42x7mm | 6806
- 35x47x7mm | 6807
- 40x62x12mm | 6908
- 1/2x1 1/8 x 5/16 | R8
- 1/2x3/4x5/32 | R1212
- 1/4x1/2x3/16 | R188
- 1/4x3/8x1/8 flanged | FR168
- 1/4x3/8x1/8 | R168
- 1/4x5/8x.0196 | R4
- 1/8x1/4x7/64 | R144
- 1/8x3/8x5/32 | R2
- 1/8x5/16x9/64 flanged| FR2-5
- 1/8x5/16x9/64 | R2-5
- 3/8x5/8x5/32 | R1038
- 3/16x1/2x3/16 | R3
- 3/16x3/8x1/8 | R166
- 3/16x3/8x1/8 Flanged | FR166
- 3/16x5/16x.1094
- 3/16x5/16x1/8 Flanged | FR156
- 3/16x5/16x1/8 | R156
- 5/32x5/16x1/8 | R155
- Agama
- ARC
- Associated
- Awesomatix
- AXIAL Racing
- Basher
- Capricorn
- CEN Racing
- Corally
- ECX
- G Made
- GS Racing
- Helion
- Hot Bodies
- HPI
- Hyperdrive
- INFINITY
- Jammin
- Kraken
- Kyosho
- Losi
- MCD Racing
- Mugen
- O'Donnell
- Schumacher
- Serpent
- Shepherd Micro Racing
- SWORKZ
- Tamiya
- TEKNO
- Thunder Tiger
- Top Racing
- Traxxas
- Vaterra
- VBC
- XRAY
- Alfa Romeo
- Audi
- Bentley
- BMW
- Dodge
- FORD
- Ferrari
- Honda
- International Harvester
- Lamborghini
- Lexus
- Maserati
- McLaren
- Mercedes
- Nissan
- Porsche
- Range Rover
- Tesla
- Toyota
- VW
- 1/2"x20
- 7/16-20
- M12x1.25x25
- M12x1.25x27
- M12x1.25x28
- M12x1.5x28
- M12x1.5x35
- M12x1.5x40
- M12x1.5x45
- M12x1.5x50
- M12x1.5 Nuts
- M12x1.5x75 studs
- M12x1.5x90 studs
- M14x1.25x28
- M14x1.25x35
- M14x1.25x43
- M14x1.25x45
- M14x1.5 Nuts
- M14x1.5x28
- M14x1.5x29
- M14x1.5x32
- M14x1.5x33
- M14x1.5x34
- M14x1.5x35
- M14x1.5x37
- M14x1.5x38
- M14x1.5x39
- M14x1.5x42
- M14x1.5x45
- M14x1.5x44
- M14x1.5x49
- M14x1.5x52
- M14x1.5x60
- M14x1.5x62
- M14x1.5x69
- M14x1.5x72
- M14x1.5x80
- M14x1.5x70 Studs
- M14x1.5x80 Studs
- M14x1.5x77
- M15x1.25
- M15x1.25x45
- M3x5
- M3x6
- M3x7
- M3x8
- M3x10
- M3x12
- M3x14
- M3x15
- M3x16
- M3x18
- M3x20
- M3x23
- M3x28
- M3x30
- M3x32
- M3x40
- M4x5
- M4x6
- M4x8
- M4x10
- M4x12
- M4x14
- M4x15
- M4x16
- M4x20
- M4x25
- M4x30
- M4x35
- M4x40
- M5x10
- M5x12
- M5x15
- M5x16
- M5x18
- M5x20
- M5x23
- M6x15
- M6x20
- M6x25
- M6x30
- M6x65
- M8 Nut
- M8x20
- M8x20 Flanged
- M8x24
- M8x25 Flanged
- M8x30 Flanged
- M8x35
- M8x35 Flanged
- M8x40 Flanged
- M8x45 Flanged
- M8x50 Flanged
- M10x25
- M3 Titanium Nut
- M4 Titanium Nut
- M5 Titanium Nut
- 1/2"x20
- 5/16-18
- 3/8-24
- 5/16-24
- 7/16-20
- 10/32-24
- 2x5x2.5mm | MR52
- 2x6x2.5mm | MR62
- 3x6x2.5mm | MF63
- 3x6x2.5mm | MR63
- 3x7x3mm | 683
- 3x8x3mm | MR83
- 3x8x4mm | 693
- 3x10x4mm | 623
- 4x8x3mm | MR84
- 4x8mm Flanged MF84
- 4x7x2.5mm | MR74
- 4x8x3mm | MR84
- 4x9x4mm 684
- 4x10x4mm | MR104
- 4x11x4mm | 694
- 4x13x5mm | 624
- 5x8mm Flanged
- 5x8x2.5mm | MR85
- 5x9x3mm | MR95
- 5x9x3mm Flanged | MF95
- 5x10x3mm
- 5x10x4mm flanged | MF104
- 5x10x4mm | MR105
- 5x11x4mm | MR115
- 5x11x5mm
- 5x12x4mm
- 5x13x4mm
- 5x14x5mm | 605
- 5x16x5mm | 625
- 6x10x3mm | MR106
- 6x10x3mm Flanged | MF106
- 6x12x4mm | MR126
- 6x12x4mm Flanged | MF126
- 6x13x5mm | 686
- 6x15x5mm | 696
- 6x16x5mm
- 6x19x6mm | 626
- 7x11x3mm | MR117
- 7x13x4mm | MR137
- 7x14x5mm | 687
- 7x17x5mm | 697
- 7x19x6mm | 607
- 7x22x7mm | 627
- 8x14mm
- 8x14x4mm | MR148
- 8x14x4mm Flanged | MF148
- 8x16x5mm | 688
- 8x16x5mm Flanged | MF688
- 8x19x6mm | 698
- 8x22x7mm | 608
- 9x17x5mm | 689
- 9x20x6mm | 699
- 10x15x4mm flanged | F6700
- 10x15x4mm | 6700
- 10x16x4mm
- 10x16x5mm | MR1016
- 10x19x5mm | 6800
- 10x22x6mm | 6900
- 10x26x8mm | 6000
- 10x28x8mm | 16100
- 12x18x4mm | 6701
- 12x21x5mm | 6801
- 12x24x6mm | 6901
- 12x28x8mm | 6001
- 13x19x4mm
- 13x20x4mm
- 14x25.4x6mm
- 14x25.8x6mm
- 15x21x4mm | 6702
- 15x24x5mm | 6802
- 15x24x5mm Flanged | F6802
- 15x26x7mm | 15267
- 15x28x7mm | 6902
- 15x32x9mm | 6002
- 17x26x5mm | 6803
- 17x28x7mm | 17287
- 17x30x7mm | 6903
- 17x40x12mm | 6203
- 18x30x7mm | 18307
- 20x27x4mm | 6704
- 20x32x7mm | 6804
- 20x42x12mm | 6004
- 20x47x14mm | 6204
- 24x37x7mm
- 25x37x6mm | 6805-6
- 25x37x7mm | 6805-7
- 25x52x15mm | 6205
- 29x42x7mm | 6806/29
- 30x42x7mm | 6806
- 35x47x7mm | 6807
- 40x62x12mm | 6908
- 1/2x1 1/8 x 5/16 | R8
- 1/2x3/4x5/32 | R1212
- 1/4x1/2x3/16 | R188
- 1/4x3/8x1/8 flanged | FR168
- 1/4x3/8x1/8 | R168
- 1/4x5/8x.0196 | R4
- 1/8x1/4x7/64 | R144
- 1/8x3/8x5/32 | R2
- 1/8x5/16x9/64 flanged| FR2-5
- 1/8x5/16x9/64 | R2-5
- 3/8x5/8x5/32 | R1038
- 3/16x1/2x3/16 | R3
- 3/16x3/8x1/8 | R166
- 3/16x3/8x1/8 Flanged | FR166
- 3/16x5/16x.1094
- 3/16x5/16x1/8 Flanged | FR156
- 3/16x5/16x1/8 | R156
- 5/32x5/16x1/8 | R155
- Agama
- ARC
- Associated
- Awesomatix
- AXIAL Racing
- Basher
- Capricorn
- CEN Racing
- Corally
- ECX
- G Made
- GS Racing
- Helion
- Hot Bodies
- HPI
- Hyperdrive
- INFINITY
- Jammin
- Kraken
- Kyosho
- Losi
- MCD Racing
- Mugen
- O'Donnell
- Schumacher
- Serpent
- Shepherd Micro Racing
- SWORKZ
- Tamiya
- TEKNO
- Thunder Tiger
- Top Racing
- Traxxas
- Vaterra
- VBC
- XRAY
- Alfa Romeo
- Audi
- Bentley
- BMW
- Dodge
- FORD
- Ferrari
- Honda
- International Harvester
- Lamborghini
- Lexus
- Maserati
- McLaren
- Mercedes
- Nissan
- Porsche
- Range Rover
- Tesla
- Toyota
- VW
- 1/2"x20
- 7/16-20
- M12x1.25x25
- M12x1.25x27
- M12x1.25x28
- M12x1.5x28
- M12x1.5x35
- M12x1.5x40
- M12x1.5x45
- M12x1.5x50
- M12x1.5 Nuts
- M12x1.5x75 studs
- M12x1.5x90 studs
- M14x1.25x28
- M14x1.25x35
- M14x1.25x43
- M14x1.25x45
- M14x1.5 Nuts
- M14x1.5x28
- M14x1.5x29
- M14x1.5x32
- M14x1.5x33
- M14x1.5x34
- M14x1.5x35
- M14x1.5x37
- M14x1.5x38
- M14x1.5x39
- M14x1.5x42
- M14x1.5x45
- M14x1.5x44
- M14x1.5x49
- M14x1.5x52
- M14x1.5x60
- M14x1.5x62
- M14x1.5x69
- M14x1.5x72
- M14x1.5x80
- M14x1.5x70 Studs
- M14x1.5x80 Studs
- M14x1.5x77
- M15x1.25
- M15x1.25x45
- M3x5
- M3x6
- M3x7
- M3x8
- M3x10
- M3x12
- M3x14
- M3x15
- M3x16
- M3x18
- M3x20
- M3x23
- M3x28
- M3x30
- M3x32
- M3x40
- M4x5
- M4x6
- M4x8
- M4x10
- M4x12
- M4x14
- M4x15
- M4x16
- M4x20
- M4x25
- M4x30
- M4x35
- M4x40
- M5x10
- M5x12
- M5x15
- M5x16
- M5x18
- M5x20
- M5x23
- M6x15
- M6x20
- M6x25
- M6x30
- M6x65
- M8 Nut
- M8x20
- M8x20 Flanged
- M8x24
- M8x25 Flanged
- M8x30 Flanged
- M8x35
- M8x35 Flanged
- M8x40 Flanged
- M8x45 Flanged
- M8x50 Flanged
- M10x25
- M3 Titanium Nut
- M4 Titanium Nut
- M5 Titanium Nut
- 1/2"x20
- 5/16-18
- 3/8-24
- 5/16-24
- 7/16-20
- 10/32-24
1441 products

Mugen MBX7 Eco Ceramic Bearing Kit
Regular price $99.99 Sale price $67.49 Save $32.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
Mugen MBX7 Eco Ceramic Ball Bearing Kit. If you are looking for the MBX7 Ceramic Bearing kit please click here.

Mugen MBX7R Eco Ceramic Bearing Kit
Regular price $109.99 Sale price $79.99 Save $30.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

Mugen MBX7T Ceramic Bearing Kit
Regular price $109.99 Sale price $69.99 Save $40.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

Mugen MBX7TE Ceramic Bearing Kit
Regular price $109.99 Sale price $68.99 Save $41.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

Mugen MBX8 MBX8R MBX8TR Ceramic Bearings
Regular price $149.99 Sale price $89.99 Save $60.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
Mugen MBX8 Ceramic Ball Bearing Kit which works for all versions including the MBX8R and MBX8TR
The MBX8 Eco is different so please make that selection if you have an Eco model.

MUGEN MRX3 Ceramic Bearing Kit
Regular price $99.99 Sale price $74.99 Save $25.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

MUGEN MRX3 Polyamide Sealed Ball Bearing Kit
Regular price $49.99 Sale price $37.49 Save $12.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

MUGEN MRX4 Ball Bearing Kit Polyamide Sealed
Regular price $49.99 Sale price $37.49 Save $12.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
Dual Super Polyamide Sealed Bearing Kit for the Mugen Seiki MRX4
This ball bearing kit contains the following:
4 - 6x10 mm
4 - 12x18 mm
4 - 6x13 mm
8 - 12x21 mm
2 - 10x15 mm flanged
2 - 5x10 mm flanged
2 - 5x10 mm

MUGEN MRX4 Ceramic Bearing Kit
Regular price $99.99 Sale price $74.99 Save $25.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
CERAMIC NITRIDE PRO SERIES CERAMIC BALL BEARING KIT for the Mugen Seiki MRX4 This ceramic bearing kit contains the following ball bearings:
4 - 6x10 mm
4 - 12x18 mm
4 - 6x13 mm
8 - 12x21 mm
2 - 10x15 mm flanged
2 - 5x10 mm flanged
2 - 5x10 mm

MUGEN MRX4R Ball Bearing Kit Polyamide Sealed
Regular price $49.99 Sale price $37.49 Save $12.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
Dual Super Polyamide Sealed Ball Bearing Kit for the Mug en Seiki MRX4
This ball bearing kit contains the following:
4 - 6x10 mm
4 - 12x18 mm
4 - 6x13 mm
8 - 12x21 mm
2 - 10x15 mm flanged
2 - 5x10 mm flanged
2 - 5x10 mm

MUGEN MRX4R Ceramic Bearing Kit
Regular price $99.99 Sale price $89.99 Save $10.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
CERAMIC NITRIDE PRO SERIES BALL BEARING KIT MUGEN MRX4R
This ceramic bearing kit contains the following:
4 - 6x10 mm
4 - 12x18 mm
4 - 6x13 mm
8 - 12x21 mm
2 - 10x15 mm flanged
2 - 5x10 mm flanged
2 - 5x10 mm

Mugen MRX4X Ceramic Bearing Kit
Regular price $109.99 Sale price $74.99 Save $35.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
Mugen MRX 4X Ceramic Nitride Pro Series Ceramic Ball Bearing Kit
This kit is an upgraded version of the World Champion winning MRX4. The MRX-4X has new suspension parts, and all the high-end options that where sold separately now all in one kit.
Features
- Rear Upper Arm (2mm Shorter)
- Brake Bracket & Rear Upper Arm Mount for short rear upper arm
- Rear upright (Adjustable wheel offset)
- Front bulkhead. You can change the tension of the belt (5 different positions)
- Rear bulkhead. You can change the tension of the belt (5 different positions)
- New Eccentric Hub
- 5mm New Rear Lower Arm Mount
- New Battery Holder (FRP) & Chassis
- New Long rear body Mount Arm & Rear Body
This ceramic bearing kit contains the following ceramic ball bearings
4 - 6x10 mm
4 - 12x18 mm
4 - 6x13 mm
8 - 12x21 mm
2 - 10x15 mm flanged
2 - 5x10 mm clutch bearings
2 - 5x10mm flanged
Mugen MRX5 Ceramic Bearing Kit
Regular price $179.99 Sale price $74.99 Save $105.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
This is a ceramic bearing kit for the all new Mugen Seiki MRX5 from our Ceramic Nitride Pro Series World Champion bearing series. Now available!

Mugen MRX5 WC Spec Ceramic Bearing Kit
Regular price $109.99 Sale price $87.99 Save $22.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

Mugen MRX6 Ceramic Bearings
Regular price $169.99 Sale price $109.99 Save $60.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
Mugen MRX6 Ceramic Bearings full and complete bearing kit from our world famous Ceramic Nitride Pro Series collection

MUGEN MST1 Ceramic Bearing Kit
Regular price $89.99 Sale price $67.49 Save $22.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

MUGEN MST1 Polyamide Sealed Ball Bearing Kit
Regular price $49.99 Sale price $37.49 Save $12.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

Mugen MTC1 MTC2 MTC2R Ceramic Bearings
Regular price $99.99 Sale price $74.99 Save $25.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
Mugen MTC1, MTC2 or MTC2R Ceramic Bearing Kit please make your selection from the list.
MTC2 Ceramic Bearing kit contains:

MUGEN MTX2 PRO SPEC Ceramic Bearing Kit
Regular price $89.99 Sale price $67.49 Save $22.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

MUGEN MTX2 PRO SPEC Polyamide Sealed Ball Bearing Kit
Regular price $49.99 Sale price $37.49 Save $12.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

MUGEN MTX3 Ceramic Bearing Kit
Regular price $99.99 Sale price $74.99 Save $25.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

MUGEN MTX3 Polyamide Sealed Ball Bearing Kit
Regular price $49.99 Sale price $37.49 Save $12.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!

MUGEN MTX4 Ball Bearing Kit Polyamide Sealed
Regular price $49.99 Sale price $37.49 Save $12.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
Dual Super Polyamide Sealed Ball Bearing Kit MUGEN MTX4
Our ball bearing kit includes
4 - 10x15 mm
7 - 5x8 mm
2 - 5x10 mm Flanged
8 - 6x13 mm
4 - 12x18 mm

MUGEN MTX4 Ceramic Bearing Kit
Regular price $99.99 Sale price $74.99 Save $25.00Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
CERAMIC NITRIDE PRO SERIES CERAMIC BALL BEARING KIT MUGEN MTX-4
Our ball bearing kit for this legendary car includes
4 - 10x15 mm
7 - 5x8 mm
2 - 5x10 mm Flanged
8 - 6x13 mm
4 - 12x18 mm

MUGEN MTX4R Ball Bearing Kit Polyamide Sealed
Regular price $49.99 Sale price $37.49 Save $12.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
Dual Super Polyamide Sealed Ball Bearing Kit MUGEN MTX4R
Mugen Seiki Racing released the MTX4R 1/10 Touring car as an upgraded version of the World Champion winning MTX4. The MTX4R has new suspension parts, new one way/solid front axle and all the high-end options that where sold separately now all in one kit. Also include is a complete set of GRP foam tires, Aluminum Wheel Hubs New Front Lower Suspension Arm allowing for more steering from the front upright Graphite Rear Upper Arm Mount. A new front upright has a 2 degree king pin angle for better steering. Further upgrades are front universal Joint Sets, rubber front belt, rubber rear belt, rubber middle belt, rear universal joint set. A new front one way drive axle can be used as a one-way or it can be converted to a solid front axle by locking up the one-way. Complete adjustability for all racing conditions New Front Joint Cup Ventilated Brake Disk Aluminum Engine Mount.
Our ball bearing kit makes this new setup fly. Here's what's included:
4 - 10x15 mm ball bearings
7 - 5x8 mm ball bearings
2 - 5x10 mm Flanged ball bearings
8 - 6x13 mm ball bearings
4 - 12x18 mm ball bearings

MUGEN MTX4R Ceramic Bearing Kit
Regular price $109.99 Sale price $67.49 Save $42.50Choose "Shop Pay" at checkout to pay in 4 easy interest free installments!
MUGEN MTX4R Ceramic Nitride Pro Series Ceramic Ball Bearing Kit
Mugen Seiki Racing released the MTX4R 1/10 Touring car as an upgraded version of the World Champion winning MTX4. The MTX4R has new suspension parts, new one way/solid front axle and all the high-end options that where sold separately now all in one kit. Also include is a complete set of GRP foam tires, Aluminum Wheel Hubs New Front Lower Suspension Arm allowing for more steering from the front upright Graphite Rear Upper Arm Mount. A new front upright has a 2 degree king pin angle for better steering. Further upgrades are front universal Joint Sets, rubber front belt, rubber rear belt, rubber middle belt, rear universal joint set. A new front one way drive axle can be used as a one-way or it can be converted to a solid front axle by locking up the one-way. Complete adjustability for all racing conditions New Front Joint Cup Ventilated Brake Disk Aluminum Engine Mount.
Our ceramic ball bearing kit makes this new setup fly. Here's what's included:
4 - 10x15 mm ceramic bearings
7 - 5x8 mm ceramic bearings
2 - 5x10 mm Flanged ceramic bearings
8 - 6x13 mm ceramic ball bearings
4 - 12x18 mm ceramic ball bearings