TDI style consists of a single-piece (double) inner ring plus two single outer rings.It is normally supplied complete with an outer-ring spacer as a pre-set assembly. TDI bearings can be used at fixed (locating) positions on rotating shaft applications.For rotating housing applications, the double inner ring of type TDI can be used to float on the stationary shaft. WSBC 78251D/78551 is widely used in automotive,rolling mill,mining, metallurgy,plastics machinery and other industries. If you want to know more about WSBC 78251D/78551 , welcome you contact us freely .