Temperature compensated, aneroid movement. Fully adjustable. Inch and millibar scales. Our standard barometer movements are calibrated for altitudes to 3,500' above sea level. Maintenance-free, ultra-hard finish guaranteed to NEVER tarnish Weatherproof construction for outdoor use Beveled glass Unique Slide 'n Lock Mounting System No visible mounting screws Easy removal for adjustments & battery replacement Lifetime warranty on finish and movement Dial: 85mm. Base: 105mm. Depth: 38mm. Wt: 295g.