WEEMS & PLATH Bluewater Collection Barometer Requires little maintenance; Fully adjustable, temperature compensated aneroid movement with inch and millibar scales Calibrated for altitudes to 1,500 feet above sea level; Boat barometer is constructed of precision molded high impact black styrene Splash resistant O-ring seal; Scratch and glare resistant matte-finish glass bezel Hinged bezel with knurled brass locking lug for easy access to movement; Instructions and mounting hardware included Lifetime warranty