The newest standard in reliable, heavy-duty adventuring watches, the Casio Tactical Master of G Rangeman GW9400 features innovations that transcend the traditional role a basic timepiece to provide a high-tech, multi-purpose tool suited for any situation. This watch contains a unique time calibration radio signal receiver that ensures ultra-precise timekeeping and operates on a direct-access triple sensor. The sensor button makes switching between modes simple and notifies the wearer of what mode is being used via an audible tone notification. There is an internal altimeter for measuring ascents and descents, a digital compass with magnetic declination correction to prevent abrupt movements from interrupting readings, and a barometer for predicting imminent weather changes. There is an integrated memory log, which stores altitude, pressure, temperature and time readings with space for 40 records, and the watch holds a seven month charge with no exposure to sunlight.