These units replace the magazine base plate and internal locking plate. They do not alter the capacity of the magazine and provide better comfort by adding approximately 1/2 inch of gripping surface. Fits all 9mm and 40SW models. Not for use with 45 ACP models or CW frames. Replaces the magazine floor plate adding grip length. (Two extensions per package) Fits Kahr T40, TP40, P40, K40, PM40, T9, TP9, P9, K9, PM9, MK9, MK9, PM9, PM40. Also Fits Colt Pocket Nine.These units replace the original base plate and internal locking plate. They do not alter the capacity of the magazine. These extensions will add approximately 5/8 inches additional length. Features: They are provide comfort and control without sacrificing conceal ability