Amazon.com: 608 ZZ Ball Bearings, Skate Bearings Double Shielded Miniature Ball Bearings for Skateboards, Inline Skates, Scooters ABEC 7 Bearing (8mm x 22mm x 7mm) 4PCS : Sports & Outdoors
R166 ZZ Bearing, ID 3/16 inch x OD 3/8 inch x 1/8 inch Miniature Ball Bearing, Metal Shielded and Pre-Lubricated with Grease, 3/16 inch Precision Roller Bearing (10 Pack): Amazon.com: Industrial & Scientific