Evolution gun works savage round back short action picatinny rail 0 MOA. Rail Type: One Piece Picatinny. Machined from: Domestic 6061 T6 Extruded Aluminum. Finish: Matte Black Anodizing. Center Spread: 3.930"". Overall Length: 6.670"". Height: .4"" (Top of Receiver to Top of Picatinny). Weight: 2 oz. Quick Disconnect Ring Compatible: No. Ambidextrous: Yes. Torque Specs: 20 in/lbs. Minute of Angle: 0 MOA. Action Length: Short Action. Mounting Hardware: #6-48 X 1/4 Screws and T-10 Bit Included. This Savage base will work with any short action round back Savage with an ejection port. It is also compatible with the Stevens short actions. The round back on this mount will accommodate rounded receivers, and guns that have an accu-trigger. This mount comes standard with a bevel on both sides making it ambidextrous. The entire mount and accessories are made in the USA.