ITEM NAME:Ball Metal Transfer Bearing Unit Conveyor Roller Replacment O3P6 Ball Metal Transfer Bearing Unit Conveyor Roller Replacment O3P6 The transfer unit is sealed and lubricated to prevent entry of foreign material and increase the life of the unit. Used widely for omni-directional motion, including conveyors, cargo rolling decks, robotics and industrial caster applications Product Name : Ball Transfer Unit Material : Metal Total Size : 48mm x 31mm x 21mm / 1.89" x 1.22" x 0.83" (L*W*H) Install Screw Diameter : 3.9mm / 0.154" Color : Silver Tone Weight : 38g Package : 1 x Ball Transfer Unit Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm..Used widely for omni-directional motion, including conveyors, cargo rolling decks, robotics and industrial caster applications. The transfer unit is sealed and lubricated to prevent entry of foreign material and increase the life of the unit.