UPDATE: Captain Bonhead is here - I've got a few Watched videos how to use and it was user error. I didn't take the kernel properly. As soon as I figured out how to do it, the air started pouring out. It works pretty well. A few minutes on each tire to blow air from 30psi to 20psi. In my book it's pretty fast. Sorry Jako - I know you tried to make it foolproof, but I think they made a better fool in my case! Installation for a ground truck to drive tires on dirt roads. It's billed as a "fast" deflator, but it's actually not fast. I got my 16 inch tires down from 38 to 25 psi and each tire took 10-15 minutes to get them down. They defecated, but it took forever. With just one of them, it would take an hour to get my truck into off-road condition. Build quality is good, but it doesn't work very well. The gauge mates with another tire gauge I have so it shows tire pressure accurately.