Feature A 40mm 1.6" Bottom to Ring Center, Six Screws Per Ring, Extremely Accurate w/ Full CNC Machined A Hard Anodizing, 21mm Picatinny Mount w/ 3 Crossing Bolts & Anti-Retreat Rings, Fit Max 65mm Scope Objective Lens A Can Accept Max 45 Inch / Pounds Torque Force for Big Nuts When Installing the Mount on the Picatinny Rail Picture Specification A Diameter: 34mm A Profile: 40mm / 1.6", from Bottom to Ring Center A Overall Length: 154mm / 6.1" A Mount Length: 154mm / 6.1" A Gap Length: 70mm / 2.8" A Ring Width: 26mm / 1.0" A Weight: 265g / 9.3oz A Material: 6061-T6 A Finish: Black matte with hard anadizing A Mountinng: 21mm Picatinny A High-durability aluminum alloy in black matte, designed for big recoil calibers A Do not use over 18 inch / pounds of torque on the scope rings&'; screws A Suggest 25 inch / pounds (Can Accept Max 45 Inch / Pounds) torque force for big nuts when installing the mount on the picatinny rail