Samson Manufacturing Corp. Polymer Medium Grenade Grip, Vertical Foregrip, M-LOK Compatible, Matte Finish, Black 04-01047-18 Samson medium grenade style vertical grip is now available in polymer" and utilizes Samsons current aluminum M-LOK" KeyMod" and Evolution mounting system. The two-piece design allows you to remove the grip from the rifle while leaving the attachment lug in place. Samson Vertical Grips are made of solid aluminum and stainless steel for their unmatched durability and dependability.