This means an excellent 1.3" AMOLED with the Always-On Display functionality, on-board GPS and tracking for over 100 sports and activities. There’s the usual array of health tracking features that monitor your heart rate, blood oxygen saturation, sleep and stress. Are the upgrades enough to justify the $180/ €170/ INR 12,999 asking price when the OG T-Rex is still available for far less? Let’s find out in our Amazfit T-Rex Pro review.