The 21300, 22200, 22300, 23100, 23200, 24000, 24100 and 23900 series of THB Spherical Roller Bearings are made of chrome steel rings and rollers, steel nylon and brass integral cages with a precision of P0 and P6. The CA is a double row symmetrical roller with an inner ring ride, the MA has an outer ring ride and the MB is a double row asymmetrical roller with a brass cage and an inner ring ride. The CTN1 is a nylon cage with double row symmetrical roller. The K is a 1:12 and the K30 is a 1:30 tapered bore bearing. The W33 is a lubricated outer ring with three oil holes. The C2/C3/C4 has C2, C0, C3 and C4 internal clearance series.