16-Pack RM2-2RS 3/8'' V-Groove Roller Ball Bearing W2-2RSRM2 2RS V Groove Guide Bearings Set of 16 3 8" Rubber Sealed Track Rollers This set of 16 RM2 2RS V groove guide bearings is made for linear track systems that demand smooth, sealed performance. With rubber seals on both sides, these hardened steel rollers keep out dust and debris ideal for gantries, motion rails, and CNC setups. Inner diameter (d): 3 8" (9. 525mm) Outer diameter (D): 30. 73mm V groove width (A): 18. 24mm Bearing width (C): 11. 1mm