A multi-sport, swim-proof GPS watch ideal for tri-athletes and dedicated athletes. The Forerunner 310XT has a battery life of +/- 20 hour and is waterproof (IPX7), making it an indispensable training tool. With a high-sensitivity GPS receiver and HotFix satellite prediction, the Forerunner 310XT locates your position simply, quickly and precisely and maintains its GPS location even in heavy cover and near tall buildings and trees.