PRO TREK, wrist gear for nature lovers everywhere.
History of Triple Sensor Evolution. 
- Triple Sensor, Ver. 1 (1994-2001)
Birth of Triple Sensor,
1st triple sensor Ver.1, PRO TREK ATC-1100 debuted in 1994. Operating on battery power, it revolutionized the wrist watch with its ability to measure directions (continuous measurement duration) , barometric pressure / altitude and temperatures.
- Triple Sensor, Ver. 2 (2002-2012)
1st Triple sensor Ver.2 , PRO TREK PRG-50 released in 2002. First triple sensor operating on Solar Power.
- Triple Sensor, Ver.3 (2013)
Next-Generation Triple Sensor realized through advanced sensor technologies. Triple Sensor Ver. 3, offering faster, longer, more accurate readings.
Pressure Sensor: Altimeter / Barometer , Measures altitudes to the nearest meter at 1-second intervals.
Direction Sensor: Compass , Measures bearings continuously for 60 seconds.
Pressure / Temperature Sensor: Barometer / Thermometer , Sudden atmospheric pressure change alarm.
Triple sensor measures directions, atmospheric pressure/ temperatures and altitudes, abd shows these and other measurement data on a high-visibility display. In this pursuit of utility as serious outdoor gear capable of detecting nature’s changing faces promptly under any circumstances, PRO TREK continues to advance on its patch of perpetual evolution. Today, Casio’s acclaimed sensor technology has given birth to the next-generation Triple Sensor, Ver. 3, heir to great strides in evolution. The extensive PRO TREK line-up satisfies demands in wide ranging outdoor arenas, and supports everyone who challenges new fields.