8-Pack RM2-2RS 3/8 V-Groove Guide Ball Bearings - Sealed W2-2RSRM2 2RS V Groove Guide Bearings Set of 8 3 8" Rubber Sealed Track Rollers This 8 pack of RM2 2RS V groove guide bearings offers reliable, sealed performance for linear track systems, gantries, and motion rails. Made from hardened steel and rubber sealed on both sides, these bearings are built for durability and smooth, debris resistant rolling. Inner diameter (d): 3 8" (9. 525mm) Outer diameter (D): 30. 73mm V groove width (A): 18. 24mm Bearing width