Recharge Apple Watch Power and Travel case - Grey/Black Compatible with Apple Watch 38mm and 42mm For use with your existing model. Fits 3.3' and 6.6' Apple magnetic charging cables. 1000 mAh lithium-polymer battery Delivers reliable power to replenish your device. Micro USB input Allows easy connectivity. Surge, overcharge and overheat protection Safeguards your device. Protective travel case Makes it easy to take the charger on the go.