Feature A 100% avoid CANT A 30mm Diameter with 25.4mm 1" Adapter A Air Bubble Level on Side A Easy to Use A Designed for Real Firearms A Full Metal A See-through A Light and Compact Picture Specification A Diameter:30mm with 1" adapter A Length:50mm(2.0 inch) A Ring Width:21mm(0.8 inch) A Rail Length:45mm(1.8 inch) A Weigth:33g (1.2 ounce) A Finish:Black matte A Anti Cant Device mount designed for real fire arms A Air bubble level on side indicating the level condition A Build-in see-through picatinny rail 4 slots A High quality 6063 T6 aircraft grade aluminum alloy A Including items: hex key, 25.4mm 1" adapter