The build quality...poor! Not so much the strap around it as much as the point where the band attaches to the strap at the placement point, that is, if you decide for some reason to reposition it often to charge it or change the strap, it definitely won't hold! As the friend below said, not ergonomic at all either! It fastens the opposite way from the factory strap, internally, so you have to exert force every time to find the gap!