The day after his arrival, HS stack. Not great for a new watch. I replace it (not very convenient because the battery is blocked by a mini-screw), but AA did, with mini screwdriver. But my biggest problem is that winding, one of the 4 cover screws turning in a vacuum. My son took it with him in the shower and took the water tightness is no longer guaranteed after this assembly. In view of these problems, I recommend.