Saili Digital Bevel Box Angle Gauge Meter Digital Protractor 360 degrees Magnets Base Digital Inclinometer Electronic Protractor with Battery Power-off automatically in 5 minutes. Aluminum alloy enclosure (light weight and durable). Relative/absolute measurement interchange at any position. ith 3 built-in magnets in measuring surface, which is convenient to be attached to the object measuring workpiece. Portable size, convenient to co-work with other measuring tools and enlarge measuring range