Operating system Wear OS Memory storage capacity 32000 MB Special features eSIM Cellular Calling, Health Tracking, Multiple Workout Modes, Rugged Durability Battery capacity 21 days Connectivity technology Bluetooth, Cellular About this item 【Futuristic planetary aesthetics】HUAWEI WATCH 4 Pro brings the boundless fantasy of outer space into your orbit, with its durable aerospace-grade titanium case and scintillating, star-like sheen. The watch's spherical sapphire glass is built to face the hazards you might encounter. With the watch's LTPO screen and fresh AOD watch faces, you can see key information at a glance. 【Phone-Free Smart Features】HUAWEI WATCH 4 Pro keeps you plugged in phone-free, with eSIM One number and eSIM Standalone Number. Make calls, send and receive SMS messages all on your watch. 【Health at a Glance】Health Glance tracks seven key indicators all at one time, including the heart rate, SpO2 level, respiratory overview, and cardiovascular health, the results of which can be printed out and shared. 【More Ways to Stay Fit】Choose from 100+ workout modes, including niche outdoor activities like free dives and hikes. The mountain hiking watch face displays trail-ready data covering altitude, atmospheric pressure, step count, location, and SpO2. It also offers route back with map. 【Rugged and Durable】The aerospace-grade titanium case fuses with the sapphire glass cover to give you ultimate protection, while water resistance supports free diving to a maximum depth of 30 m. 5 ATM and IP6X water and dust resistance protect your watch against liquid spills and damage while underwater. Compatible with Android and iOS Phones