42 mm Aluminium Case, Strap Size fits 130-200mm wrists-- S1P dual-core processor, Ion-X glass, OLED Retina display with Force Touch, Digital Crown-- Heart rate sensor, accelerometer and gyroscope, Ambient light sensor-- Speaker and microphone, Wi-Fi (802.11b/g/n 2.4GHz), Bluetooth 4.0-- Splash resistant, Up to 18 hours of battery life3, Composite back, watchOS 9--