4pcs SG22 U Groove Track Guide Bearing 8×22.5×14.5mm Roller Wheel GCr15 Steel
General Information：[1]U-type pulley bearing fits the rail track system. Widely used in door and window to track and drive mechanical equipment.[2]SG20 bearings are Sealed on both sides to keep lubricant in[3]Chromium Steel long-life bearings, smooth and low noise[4]ABEC Tolerance 1 (P0), Z1 Noise Level for most general use[5]U Groove Bearing: I.D.=8mm, O.D.=22.5mm, Thickness=14.5mm, Groove width=10mm, Groove depth= 2.5mm.