Sturdy but elegant, the batteries fit in perfectly, and the details like the unit showing me the charge level of each battery as I slide it in is so well thought out, as everything else. You would expect the check to work when you press the button on the side, of course, that's why it's there, but this was just another proof how well planned the product is. Peter recognized the need and delivered a product. Hope it sells a ton and that the next Gen maybe (yes, I'm still suggesting it) maybe includes the card reader ;-)