1.The size is MUCH BIGGER than original apple watch 44mm, if YOU DON`T LIKE BIG SIZE, please don`t place order; 2.The SIZE of the case was marked at the second picture, please read it before procurement. 3.ECG function can`t be used when put the apple watch into this case. This item is only for Apple watch series 4 44mm 2019, apple watch series 5 and apple watch series 6 2020 44mm. It`s a full sealled waterproof case for apple watch 44mm. Please Note that: Waterproof test is needed before put the case with your watch into water, if found leakage, please contact us at the first time, thanks.