(Not a) Poly 80 Glock Foregrip

Based on the cover pic of "The Glock Exotic Weapons System". This was designed to be compatible with a Poly 80 Glock frame. It utilizes a 1" long 10-32 button head screw and is best printed with the top side down.

Remember, adding such things to a pistol changes the classification with the ATF, so make sure that you have the proper paperwork before doing so.