This listing is for 4 piece/s.The basic design of these products is essentially that of a conventional rolling bearing, except that they have a thick-walled outer ring. Stud type track rollers have a shaft stud at one end. In the majority of applications, the outer ring is subjected to circumferential load, i.e. the outer ring rotates while the inner ring or stud remains stationary. The thick walled outer ring prevents excessive deformation of the track roller and ensures that the rolling element set is uniformly loaded Specifications Roller diameter: 47 mm Bore diameter: 20 mm Roller width: 24 mm Roller shape: Crowned Bearing element: Needle Rollers Overall width: 25 mm Closure type: Sealed Operating temperature range: -30 to +250 °F Radial static load capacity: 10791 lbs Roller material: Chrome Steel Maximum rpm: 2600 rpm Lubrication hole location: Inner Ring Finish/coating: Black Oxide Series: Metric CAMROL (MCYR)