The Flatline Ops Halo-X is a game changer. Originally designed for Leupold's Mark 5HD (U.S. Army PSR, M110 and MK22) military optic programs, this unique and precision engineered level is now available for civilian use. Machined from ultra-strong 7075-T6 aircraft aluminum, this is the lightest and strongest level. Weighing less than half an ounce, and only .3125"; wide, it's one of the most minimal level for crowded scope tubes with extensive vegetation.