Inner Diameter - 4mm

4x12x5mm U-Groove Pulley Ball Bearing

DDLF940ZZ Stainless Steel Flanged Miniature Bearing 4x9x4mm

4mm Bore Bearing - 13mm Pulley U-Groove Track Roller Bearing 4x13x7mm

624-2RS Bearing 4x13x5mm - Sealed - Miniature

624-Z Ball Bearing Bore ID 4mm OD 13mm Width 5mm

694 Bearing Open 4x11x4 Miniature

10-Pack S694ZZ 4x11x4 Stainless Steel Shielded Miniature Bearings

4mm Bore Plastic Roller Ball Bearing - Nylon Tire - 14mm OD - 4x14x4mm

4x8x2.5mm Ball Bearing - Shielded - Miniature

10-Pack Shielded 4x10x3 Miniature Bearing

684-2RS Ball Bearing - Sealed - Miniature - 4x9x4mm

MR74-2RS Ball Bearing ID 4mm OD 7mm Width 2mm

MR104-ZZ Ball Bearing Double Shielded ID 4mm OD 10mm Width 4mm

2-Pack Ball Bearings Fit Shimano Stradic 2500 Spinning Reel

10-Pack Ball Bearings for Yomega YoYos

10-Pack Flanged Bearings F684ZZ 4x9x4mm - Shielded - Miniature

10-Pack Yo-Yo for Yomega YOYO Bearing

10-Pack 4x10mm - Double Shielded 4x10x4 Miniature Bearing

10-Pack S684-2RS 4x9x4 Stainless Steel Sealed Miniature Bearings

HF0406 One-Way Needle Bearing/Clutch 4x8x6mm Miniature

10-Pack 4x7x2.5mm Ball Bearings - Metal Shielded - 4mm Bore

10-Pack S684ZZ 4x9x4 Stainless Steel Shielded Miniature Bearings

10-Pack SWAS-4-8-1-AW NBK Stainless Steel Adjust Metal Washer -Made in Japan-

4x10mm Full Ceramic Ball Bearing 4x10x4mm - Miniature - ZrO2 - Sealed