The major physical difference between the Mi Band 3 and its predecessor is in the display. The Mi Band 2 had a touchscreen, but it also had a small navigation button under it. The Mi Band 3 replaces that with a full touchscreen, a 0.78-inch OLED display up from the 0.42-inch display on the Mi Band 2. The display sports a 128 x 80 pixel resolution, which is enough room to fit 26 Chinese characters on a single screen. Inside a 110 mAh battery a built-in heart monitor. All of these internals will survive in up to 50 meters of water, bringing it into waterproofing parity with the Fitbit Ionic and Versa. On the outside, you’ve got a new elastomer band that comes in your choice of blue, black or red.