Amazfit kicked off its rugged smartwatch lineup with the "T-Rex" back in 2020. It comes in a robust army design and it has also secured MIL-STD-810G certifications. That means the Amazfit T-Rex can endure everything from extreme heat (70°C), cold (-40°C), humidity (240h), and other harsh environmental conditions. Up front, it has a 1.3" AMOLED display with Corning Gorilla Glass 3 protection and anti-fingerprint coating. Amazfit ships a skin-friendly silicon strap with a breathable design that keeps the user's wrist sweat-free and non-sticky. This watch is water resistant up to 50 meters (5 ATM) so you can go swimming without worries by wearing it. Its big 390mAh battery is also rated to last up to 20 days. In terms of health tracking, Amazfit T-Rex brings features like 24/7 heart rate, SpO2 monitoring, etc.