Double Plain Linear Bearing DFPMR40C 40mm ID Round Flange End, Compensated ClearanceExtended Plain Linear Bearing with a 40mm compensated ID consisting of a round flanged aluminum housing (end mount) with a self lubricating FrelonGold lining for maintenance free linear, rotational or oscillating motion in harsh conditions like extreme heat, dirt, and vibration. Extended closed aluminum housing with self lubricating FrelonGOLD liner Round Flanged End Compensated ID running clearance (0. 0015" per side) Optional liners include