The Pearce PG-26G4 Grip Extension replaces the magazine base plate and retain all other factory components on Generation 4 (only) Glock models 26/27/33/39. The PG-26 forms the next logical finger positioning feature to provide control and comfort without sacrificing concealability. These units will add approximately 1" additional length for better control and comfort, yet blend with the contours and texture of the handgun giving a factory appearance. It does not alter the capacity of the magazine. Will NOT fit Generation 1, 2 or 3 models..