T=Machined Laminated Phenolic Cage (Single Row Radial Or A. C. Bearings). DUM=(DM-Ax. Int. Cl/Pr Segment)/(DGB-SKF)=Set Of 2 Universal Bearings, Medium Preload.P4=DIMENSIONAL & RUNNING ACCURACY TO ISO TOLERANCE CLASS 4 (MORE ACCURATE THAN P5)-ABE