Samsung Galaxy Watch4, 40mm, Black, Bluetooth - Accelerometer, Gyro Sensor, Barometer, Ambient Light Sensor, Digital Compass, Optical Heart Rate Sensor, Electrical Heart Sensor - Text Messaging, Music Player - Heart Rate, Calories Burned - 16 GB - 1.50 GB Standard Memory - 1.2" - Android Wear - Bluetooth - Black - Aluminum Case - Health & Fitness - Water Resistant - IP68 Water Resistant: