Casio PRO TREK Triple Sensor Solar Mens Outdoor Watch Black PRW3510Y-8The PRW3500 series of Tough Solar Power watches with Triple Sensor (Altimeter Barometer, Thermometer & Compass) is the perfect fit for any outdoor adventurer. Casio's Version 3 technology provides a direction sensor that's 95% smaller, along with a 90% decrease in sensor power intake. Though the watch has shrunk from a physical standpoint, the technology has risen to another level specifically in its accuracy and energy efficiency. Black, 56. 9 x 53.