They work as intended nothing fancy.

Bought this for my kids ages 7 and 9. Both like this mask because it covers their noses and easily adjustable straps. I tried it on myself and also fits me comfortably. Very satisfied.

UPDATE: I discovered the top could be unscrewed, there is a round rubber ring that wasn't in the right place.
It goes around the bottom and even though it looks too big it works. Now it work but I have nothing to try it out on.

This unit does not work, I can breathe harder than it pumps air. I tried contacting the seller, not only did it take them a long time to respond but they insulted me by not reading my complaint fully and gave an explanation of how it has a inflate/deflate port on either side. It didn't cost enough to pay for return shipping so it's going in the trash. So disappointed!

Die Matratze kam schnell an, roch nicht unangenehm, das Gebläse funktioniert einwandfrei und man liegt weich und bequem auf ihr.

We bought this as a replacement for an identical one that got washed away. This one has all the identical stats in the detail description. We found the one we thought we had lost. When we had the two side-by-side we compared them. Oddly this new one was slightly smaller than the original one. Other than that it’s a good boat.

Perfect fit for my face. No water leaks. Easy to see thru.