Enables linear motion along a shaft through recirculating ball tracks arranged in a closed housing design, sealed on all sides for protection against contamination. Bore diameter is 50.0 mm, outside diameter 75.0 mm, net mass 0.659 kg. The lightweight construction keeps installed mass low while the closed design maintains ball position around the full circumference of the shaft. A relubrication facility allows grease to be replenished without dismantling the unit, supporting continuous operation between service intervals. Full sealing on all sides limits ingress of dust and moisture along the shaft path, and the adjustable angle feature permits compensation for slight misalignment between the bearing and the shaft axis during mounting. Symbol KN50-B-PP identifies bore size and this sealed, relubricatable execution within the range.