NDZ Grip Frame Slug Plug P1 for Glock Gen 1-3 Masonic Square and Compass Engraved NDZ P1 Grip Plug for GLOCK 17 19 20 21 22 23 24 25 31 32 34 35 37 38 - WILL NOT FIT GEN4 or SHORT FRAME 1000+ High Resolution Permanent Laser engraved images, will not rub off, not painted, custom engraving too - by NDZ Performance Fits flush, prevents snagging, debris from entering or reaching trigger assembly and firing pin Quick install using a tight friction fit Helps guide mag. into mag well.