The design of the cross section and the structure of the belt have been the subject of ongoing development aimed at optimising the synchronous drive. Have profile of ZA, ZAS, ZB, ZBS, MY, MR, S8M and type of MR, MY, ZBS, YU, RU, ZA, FS8M, ZR, ZAS, ZB, RHD, RHX, RPP, SL, ZD and so on