This is the heart rate watch that pairs with an iPhone and displays speed, pace, and distance on the watch face. The watch connects wirelessly via Bluetooth to an iPhone or Android-powered phone running the free MapMyRun app and displays distance traveled and pace, allowing a runner to easily monitor critical performance metrics with a quick glance. The included heart rate chest strap fits comfortably around the torso and transmits a constant ECG-accurate heart rate reading to the watch. The watch also displays calories burned, time, and date and has a built-in three axis accelerometer that estimates running pace and distance when not paired with an iPhone. Four buttons on the bezel allow a runner to quickly illuminate the face and record laps. With a durable acrylic and glass watch case and a flexible, adjustable polyurethane band. Compatible with iOS 5 and up and Android 2.1 and up. Specify Men's (Black) or Women's (Gray). 7/16" depth. Men's face is 1" Diam and Women's face is 3/4" Diam. (5 oz.)