Stainless Steel & Mud-resistant Design: Constructed with super-strong 316L stainless steel and a patented mud-resistant bridge and buttons, Amazfit T-Rex Ultra is built to withstand any kind of action. The smartwatch's HD AMOLED display can reach a peak brightness of 1,000 nits for ultra-clear visibility in any environment. Adjustable lugs ensure maximum comfort for the entirety of your epic adventures, and you can enjoy ultimate control with a responsive touchscreen and four convenient buttons.