These are reproduction pre-war screws with bastard threads and oval heads. Because the thread size varies from gun to gun even within the same model, they may not fit all guns. It has been our experience they should work on all the models listed. Haenel models I, II. III, XX, XXX, XXXX, XV, 20, 30, and 40. It is also identical to the grip screws on the models 26 and 28.