If its the 2 piece case its the M40K if the one piece its the M40SF a different head same price. Over the past thirty years in the 40 class there have been the following models FSR(1), SF(3), FP(1), VF(2), DF(2), LA, SX and the AX (1) and (2) are the same. The following are clones by others Tower 40 (1) Royal (1)(3) Leo (!)(3) Megatech or RJL (3)

DDD