This inflator is well designed, works quickly and quietly, and comes in a nice storage bag to stow away in your car. It does have one major design flaw which is the purpose of this mini-review : the screw-on valve adapter. Most inflators come with a quick-release type adapter. This one comes with a screw-on adapter. It's good because it means a secure seal, but it also means that it lets a good 2psi of air back out of your tire every time you unscrew it. The problem is that as you unscrew it, the seal is broken with the valve, but the pin in the valve is still held in so air begins to escape. If you're quick, it lets out about 2psi. If you have large fingers, are elderly, or otherwise slow at manipulating small objects in tight spaces, this could let out up to 10 psi while unscrewing it. This makes the whole inflator questionable because whilst the built-in pressure gauge is bang-on accurate while the hose is attached, it's meaningless once you unscrew the valve adapter and let a bunch of air out. In the end you will find yourself over-inflating your tyres by 2 to 3 psi just to compensate for the screw-on valve adapter. It's a shame because otherwise this is one of the best inflators I've owned.