The GTR 4 comes with a 1.43-inch AMOLED display that has 466 × 466 pixels resolution and 326PPI pixel density. The screen has tempered glass and an anti-fingerprint coating. On the other hand, the GTS 4 sports a 1.75-inch AMOLED display with 341PPI pixel density. Both smartwatches run Zepp OS 2.0 and are compatible with devices running Android 7.0 and above as well as iOS 12.0 and above. Display : Size: 1.43” (rectangular) Type: AMOLED, touch Resolution: 466 x 466p Density: 326 dpi Material: tempered glass with anti-fingerprint and anti-glare coating Technical parameters: Health sensor: BioTracker™ 4.0 PPG biometric sensor (supports blood oxygen, 4PD + 2LED) Motion sensors: Accelerometer, Gyroscope, Geomagnetic, Barometric Altimeter Other sensors: Ambient light sensor GPS: Dual band satellite positioning systems Connection: Bluetooth 5.0 BLE, WiFi 2.4 GHz Compatible devices: Android 7.0 or higher, iOS 12 or higher Battery : Capacity: 475mAh Autonomy (typical daily use): up to 14 days Charging method: magnetic base Charging time: approx. 2 hours Design : Materials: Polycarbonate bottom shell with aluminum alloy frame Strap: Fluoroelastomer (interchangeable 22mm) – Adjustable to wrists from 150 to 215 mm Waterproof rating: 5 ATM Dimensions: 46 x 46 x 10.6 mm Weight (with strap): 34 g Colour: Superspeed Black Package content : 1 x Amazfit GTR 4 Black 1 x Charging Cable 1 x User Manual