It did a good job of sealing the outlet of the bottle (LOL) I was not able to get it installed as I could not squeeze hard enough to get it out of the bottle. When I got a clamp to squeeze a little harder the hose popped off of the valve stem and then of course it came out, all over the wheel and tire. The good news is that it was an easy clean up with a garden hose. In short, I was not able to use the product which made the cost a loss and I still don't have the flat protection I wanted. It just did not want to go thru the tiny opening of the valve stem.