Pearce Grip Frame Insert Fits Glock M20 and M21 Short Frame. Fills in the bottom rear cavity in the heel of the grip body utilizing a friction fit to secure it to the frame. Helps keep debris out of the magazine well. For Glock SF (Short Frames) only. These grip frame inserts will not fit a Glock Generation 4 frame nor a standard Glock M20 or M21 frame. Specifications for Pearce Grip Frame Insert Fits Glock M20 and M21 Short Frame PGFI20SF: Manufacturer: Pearce Grip Color: Black Finish: Black Additional Features: Grip Frame Insert Gun Model: Glock 21SF Gun Make: Glock Package Contents: Pearce Grip Frame Insert Fits Glock M20 and M21 Short Frame PGFI20SF The Pearce Grip Frame Insert PGFI20SF is a quality addition to the Pearce Grip lineup. For more great deals on Gun Accessories by Pearce Grip please browse our Pearce Grip Weapon Accessories page. Pearce Grip Frame Insert PGFI20SF