Built for outdoor adventures, the Casio Pro Trek Opp Triple-Sensor Watch delivers simple style and dependable service. The watch's barometric-pressure-tendency alarm alerts you to sudden changes in pressure readings that could mean foul weather is approaching. Altimeter measures altitude in 1-meter increments. Digital display compass readings with 60 seconds of continuous measurement. Other features include sunrise/sunset data, five alarms with snooze, countdown timer and stopwatch. Low-temperature resistance keeps watch operating in temperatures as low as 14°F. Durable black resin band and case with large side buttons for easy access even when wearing gloves. Flick your wrist for full-auto LED light with Afterglow. Solar-powered rechargeable battery lasts up to nine months without exposure to sun. Water-resistant to 100 meters. Case dia: 54.6mm.