This rebuildable driveshaft has flats on the splines and fits models as per the original driveshaft for the /7 models built between 1979 - 1980: R60/7, R75/7, R80/7, R100/7T, R100T, R100RS, R100RT, R100S It also fits all 2 valve R series models built between 1981-1995. (NOT Paralevers OR R45/65)