Fit bottom 21mm picatinny and weaver rail Fit Barrel with adapter (12.5mm to 22mm, 0.5 to 0.9 inch)) Height (from top mount base to foot bottom vertically): 155mm (6.0 inch) in shortest 165mm (6.5 inch) in longest Weight (net): 220g (7.8 ounce) Easy use and installation Press down the side button to fold the bipod feet Release the feet screws to extend the length, and then fasten again Rubbber Feet avoid slip High quality aluminum alloy in durable black matte finish