DT Swiss 12 mm Thru x 142 mm SRAM XD 11-Speed Bicycle Rear Hubs
About DT Swiss - Driven by the vision of becoming a worldwide known manufacturer of bicycle components, DT Swiss expanded its product range over the years. Today DT Swiss has established itself as a leading manufacturer of spokes, nipples, hubs, rims, complete wheels as well as suspension systems.
This is hub spacing and is the width of the hub. It must match your frame specifications.
The cassette body type is the type of cassette and number of speeds the hub will accept.