Sola Aluminum Box Level with Digital Electronic Inclinometer - ENW 120,Sola Levels,ENW 120" /> Built of rugged 6063 Aluminum Alloy Can calculate angles as either degrees, millimeters or as a percentage Shockproof acrylic block-vials. Sonic welded not glued. Vials will neither crack nor break when used at the jobsite Accuracy  .3mm/M in standard position,  .75mm/M inverted Lifetime guarantee against leakage and fading of vial: In proper use of the level, vials will neither leak nor fade in the sun