Install 11mm dovetail rail
Top 21mm weaver / picatinny rail
Length: bottom 11mm dovetail mount base 75mm (3.0 inch); Top rail 100mm (3.9 inch)
Height: 16.5mm from bottom base (0.65 inch)
Weight (net): 60g (2.4 ounce)
High-durability aluminum alloy in black matt and beautiful complement
Shock proof with bottom anti-shock pin