The linear ball bearing (also called ball bushing or shaft guiding) consists of a polymeric cage with raceway segments made of hardened steel to guide the ball sets within the complete system. Recirculating balls provide unlimited stroke at low friction movement. SKF linear ball bearings and units for shaft diameter 6 mm and larger are factory pre-lubricated. Due to the applied amount of grease and the use of SKF double-lip seals (2LS), many applications will not require relubrication because in these cases the theoretical relubrication interval exceeds the bearing life. These linear bearings are lubricated with the high-performance SKF grease LGEP2.SKF linear ball bearings are also available in a range of units that feature lightweight, cast aluminum housings. Combined with SKF shafts and accessories, this complete offer can be used to develop simple, cost-effective linear guiding systems for a wide variety of applications.