Our Dual Function Spanner wrench tool is made of Steel for strength & durability. It comes with a rubber coated handle that provides a comfort grip & non-slip easy torque handle. It is used to assist in easily removing your old extension tube and installing a newer style A4 Stock. It also features a cutout to fit the receiver extension tube to remove the A1 or A2 stock. A Great tool for any Rifle Enthusiast or Gunsmith looking to work on their AR-15/M4 style rifle. Features: Heat treated, corrosion resistant Comfort grip Non-slip torque handle Mil-Spec castle nut wrench Standard length receiver extension removal wrench A1/A2 flash suppressor wrench