I was looking for a way to repair a flat tire and re-inflate that tire while on the side of the road without carrying a small air compressor. I found this and bought two to try. Just to see how much air was available in one canister, I de-flated a tire (345/40-18) and tried this. The tire shot right up, but only held about 7psi. This is a large tire, but I was expecting/hoping for 10psi. Regardless, because this kit is so easy to stow and use, I am just going to buy a few extra canisters. One suggestion is that I would like to see the inflator tool made with metal, or at least the end that attaches to the valve stem. You have to be careful with the plastic, but it works.