The Xiaomi Mi Smart Band 4 (Xiaomi Mi Band 4 in China) is a wearable activity tracker produced by Xiaomi Inc released in China on 16 June 2019, in Europe on 26 June 2019 and in India on 19 September 2019. It is 39.9% larger than its predecessor, has a super capacitive AMOLED display and features 24/7 heart rate monitoring. Specifications Specifications: Display: 0.95 inch AMOLED, full color touch screen; Colour depth: 24bit; Screen brightness: Up to 400 nits; Resolution: 120 x 240; Button: Single touch button (wake up, go back); Connectivity: Bluetooth version 5.0 BLE; NFC on some models; Mass: 22.1 g; RAM: 512KB; Storage: 16MB: Battery: LiPo, 135mAh, 20 days of battery life; Sensors: accelerometer, gyroscope, PPG heart rate sensor, capacitive proximity sensor; Waterproof: up to 50 metres, 5 atmospheres See also Xiaomi Xiaomi Mi Band Xiaomi Mi Band 2 Xiaomi Mi Band 3 Xiaomi Mi Smart Band 5 References Mi Smart Band 4 full specification Sports equipment Wearable computers Activity trackers Xiaomi Products introduced in 2019 Smart bands