M3 X 8MM Flat-Head Torx Head (Fits Burris FastFire 2 or 3 and Vortex Viper)M3 X 8MM Flat Head Torx Head. Note: We now include these screws with the purchase of the following adapters: Red Dot Adapter for the Glock Pistol M. R. A. Red Dot Adapter for the Smith & Wesson Pistol Pistol M. R. A. Red Dot Adapter for the Springfield XD(M), XDS Pistol Pistol M. R. A. Red Dot Adapter for the Ruger Mark I, II, III, IV, IV Lite, 22 45 M. R. A. The M3 X 8MM Flat Head Torx Head is required to mount your Burris FastFire 2 and Burris