The NDZ JP6 Grip Frame Insert Plug for Glock Gen 4-5 Models 17, 17L, 18, 19, 22, 23, 24, 25, 31, 32, 34, 35. Please note: This plug will not fit Gen 4-5 models utilizing the OEM Removable Backstraps. The NDZ JP6 Grip Frame Insert Plug is designed to close the open cavity at the bottom of the grip, not allowing debris to enter and reach trigger assembly and firing pin. This plug utilizes the lanyard hole for retention. Used by LE & military worldwide.