The bearing units consist of ball or roller bearing installed within a four bolt housing. The housings are made of stainless steel which provide rigidity and secure positioning for the bearing within the application. Secured by bolts, the bearing unit is high-quality and will last a long time in the application of many kinds, decreasing noise and friction. Also available in cast iron and plastic housings.  ALL 4 BOLT  STAINLESS FLANGE BEARINGS START WITH SSUCF2. PLEASE CALL 732-563-2225 IF YOU NEED ANY HELP.