If you’re in the market for a fitness tracker, you’re more than likely hoping to modify your health behavior — whether it’s remembering to walk more, tracking how often you work out, or making sure you’re working out appropriately hard when you do. The wearables market is saturated with options, but you won’t find one that’s much more affordable than Xiaomi’s latest Mi Band 4. It’s packed with features for half the price of counterparts from Fitbit and Garmin.