Linear Ball Bearing IP24GW 1.50" Closed Double WideDouble linear ball bearing, closed, with a 1. 5" inner diameter (ID). The twin size format equals two standard linear ball bearings mounted back to back for added stability. Its ball bearing design provides a low coefficient of friction and offers an advantage in cantilevered applications where plain bearings may be limited by the 2: 1 binding rule. The heat treated alloy steel shell provides durability, the balls deliver speed, and the polymer resin