Amazon.com: Power Transmission Products For Desktop 3D Printer Special Bearing 608ZZ ABEC-5 8X22X7mm Mute Speed Miniature Ball Bearings ZZ809 for Reprap Prusa i3 Parts 10PCS Ball Bearings ( Size : ABEC 5 ) :
Amazon.com: 1Pc 608ZZ ABEC-5 Bearing Caster Wheel 2.5in PU Casters for Small Carts/Doors/Hardware 64196mm Trolley Luggage Suitcase Caster DUO ER : Industrial & Scientific