Johnson 72" Aluminum Box Beam Level features three vials that read plumb, plumb & level, and Johnson Surround View Vials that reflect ambient light for easy reading. The solid block acrylic vials won't fog, leak or break, and the impact resistant ABS end caps provide durability. ABS hand grips ensure comfort during use. This level has an accuracy of up to 0.029 degree (0.5 mm/m) in the standard position, and 0.044 degree (0.750mm/m) in the inverted position.