The AAFG01 Archangel Heavy Duty Vertical Fore Grip - Aluminum. Features an O ring friction secured solid center post that provides superior strength. The fore grip and center post are CNC machined from solid T6 aircraft grade aluminum, then type III hard anodized. The grip is based upon the classic Swiss" ergonomic configuration. Precision machined to meet MIL-STD 1913 Picatinny rail specifications. Easy to install and remove; no tools required. The gripping surface is 4" and the grip is 5" overall length. This is the most no nonsense fore grip available.