The Apple Watch Series 3 model allows you to choose between a built-in GPS or cellular model. This particular version comes in a stainless steel case with a Milanese loop and measures approximately two inches (42mm) in diameter. It is built for overall information as well as health with an included heart rate sensor, accelerometer, and gyroscope. The dual-core processor and 18-hour battery allow for uninterrupted use throughout the day. It also comes with Wi-Fi and Bluetooth compatibility.