Machined from: domestic 6061 t6 extruded aluminum. Finish: silver anodized. Mounting hardware: hex head screws and wrench provided. Center spread: 2.75". Overall length of mount: 5.094". *the center spread is the distance between the two middle holes, center to center, on your receiver. This base sits at approximately 0.4"" high. This will also fit the camp carbine 9mm and camp carbine45 acp. Picatinny cross slots run the full length of the rail, which gives the shooter flexibility when mounting scope rings and other accessories. The channel in the center reduces the overall mass of the mount, weighing in at 2-3oz on average. Also, in many cases, it will not obstruct usage of factory iron sights. Egw's one piece scope mounts are the obvious choice for hunters and tactical shooters alike. This mount is a picatinny-style base and compatible with picatinny or weaver scope rings. Add egw's practical or hd scope rings to make it a complete overhaul! we machine these in our shop using one of our usa-made fadal machining centers. After machining, the mounts are tumbled, sand blasted, and type ii anodized for long lasting durability. The entire mount and accessories (from the mounting screws and wrench down to the packaging) are made in the usa. Installation: egw recommends 20 inch lbs of torque and a drip of blue loctite (loctite is available through our website and is sold separately).