Japan AI hua (EVER-TRUST) 690-pointer meter above sea level is a compact and high accuracy pressure gauge meter above sea level, such as hiking, camping, climbing, driving is an indispensable companion for outdoor activities. Barometer pointed out that the atmosphere changed relationship with the altitude changes in sea level as the base; Instrument display altitude above sea level is based on atmospheric pressure changes. Increased altitude per 100 m (328 feet) down 12 at atmospheric pressure millibars (0.36 inches of mercury). Meter above sea level are based on the principles with the same aircraft to measure the altitude meter above sea level, barometric pressure and altitude provisions are in line with international maritime atmosphere, consistent with the international standards of seafaring atmosphere.