Designed for die-hard outdoor action, and tested to MIL-STD-810G durability, Polar’s Grit X Pro smartwatch features a sunlight-readable display beneath a rugged sapphire. With GPS, HRM, between 40 and 100 hours of battery life, and waterproof to 100 meters, it is a solid, full-featured smart device. A titanium “Titan” variant is also available that is 12% lighter.