Track rollers with Gothic arch groove - type LFR
Series LFR rollers are the most widely-use and economy product among the linear motion track rollers, and they can suit to the cylindrical track.
There are two contact points between the roller and track, so the contact function is favorable.
Rollers feature double row angular contact ball bearing in its internal structure design and a thick-walled outer ring, so rollers can accommodate higher loads.
Rollers are made of high-quality bearing steel, processed by heat treatment and precision grind, and are filled with a long service life, high-grade and multi-purposes grease. Rollers mount the metal shield (KDD) or rubble seal (NPP) to prevent the dust. YITONG also can provide the rollers with concentric or eccentric pivot. Some types of the rollers can be made from the corrosion resistance stainless steel.

More information: http://www.yi-tong.com/yi-tong/en/yoke_type_track_roller.htm