The FH-M7130-B is a rear FREEHUB for a disc break from Shimano’s SLX range. The FH-M7130-B has a 12 mm E-THRU axel. In addition, the FH-M7130-B has an extra wide O.L.D spec of 157mm. Lastly it is simple to set up & gives a stiffer rear wheel option & are available in 28H, 32H.