Pearce Grips Frame Insert for Glock Fits (Non-Gen 4) models 26, 27, 33, and 39 (NOT for Gen 4) Helps keep debris out of the magazine well Friction fit holds the unit in place in the bottom rear cavity of the frame Made in the USA Helps keep debris out of the magazine well Fits Glock model 26, 27, 33 and 39 Fills cavity in the heel of the grip body