The Pearce PG-19 Grip Extensions replace the magazine base plate and retain all other factory components. They do not alter the capacity of the magazine and provide better comfort and control by adding approximately 1/2 inch of gripping surface. An optional filler piece is provided for Glock models with a semi-circular cut-out in the lower front area of the grip body. This filler piece allows for installation of the PG-19 on all Mid and Full Size Glocks. Fits Models 17,18,19,22,23,24,25,31,32,34,35,37,38 - Full Metal Lined Magazines Only..