Made from polymer material, this allows you to improve the look and functionality of the replica. The kit is compatible with most of the G17 / 18/19 series airsoft pistols. It is Mounted to the replica using a the rail under the gun barrel, and secured with an Allen screws. It has 22mm RIS / Picatinny rails on top and both sides , allowing the gun to be equipped with additional accessories , such as a red dot, flashlight or a laser target pointer.