This bumper guard and screen protector works well! Have had it on for about 6 months now, and it's been keeping up well. It fit my SE 40mm perfectly. Feels a little tight when putting on almost like it won't fit but that's expected since it has a pretty snug fit. Only issue I have is that sometimes water will get in between the bumper and watch itself with significant splashes on my wrist. Not a huge deal, just annoying having to take it off clean off the water, but that's normal, what am I expecting? Something that defies gravity?