Feature A 100% avoid CANT A 30mm Diameter A Universal Air Bubble Level A Easy to Use A Designed for Real Firearms A Full Metal A with Build-in Compass Picture Specification A Diameter:25.4mm(1 inch) A Length:49mm(1.9 inch) A Width:14mm(0.5 inch) A Weigth:25g (0.9 ounce) A Finish:Black matte A Anti Cant Device mount designed for real fire arms A Universal style bubble at any direction A Build-in compass A High quality 6063 T6 aircraft grade aluminum alloy A Including items: hex key