NDZ Grip Frame Slug Plug P6 for Glock Gen 4 Masonic Mason Calipers G Logo Engraved NDZ P6 Grip Plug for GLOCK 17 18 19 22 23 24 25 31 32 34 35 37 - GEN4 ONLY - USE without BACKSTRAP installed 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.