Pearce Grip's Grip Extension replaces the magazine base plate, but retains all other factory components. It does not alter the capacity of the magazine and will add 3/4" additional length for better control and comfort.An extension for the Glock 42 (380 cal). This extension replaces the magazine floor plate adding approximately 3/4 inches additional length resulting in better control and comfort without altering the capacity of the factory magazine. This product will not fit the Glock 43.