LME30UUAJ Linear Ball Bushing Works with 30mm Shafts 30x 47x 68 mm LME30UUAJ adjustable Linear Motion Ball Bushing works with 30mm shafts, this is an adjustable sealed linear ball bushing, with the inner diameter of 30mm, outer Diameter of 47mm, and a length of 68mm, the LME30UUAJ can be used in many CNC router applications like CNC wood router,plasma and any application that requires smooth linear motion and positioning.