I received this tool yesterday to replace some valve stems on my flatbed truck. The local shop was charging $30 a tire just to put a new valve stem in it. It turns out all four wheels on my trailer need new valve stems because they've been seated for a while. The only minor modification I had to make was to file the hook on the extraction T-handle a bit, as the first valve stem I tried to extract from the hook was slightly larger than the hole in the wheel. I did just narrowed the hook a bit with a flat file to make it easier to slip out. I had silicone spray on hand and used it to lubricate the valve stem and insertion tube. I have to say it was easier than I thought. I bought extra valve stems anyway and had no problem replacing all four valve stems on my trailer. It probably didn't take me more than 20 minutes. Worth the investment. My only concern is how long the plastic insert tube will last. It seems to be made out of fairly thick plastic, but I'll probably store the set in a cool, dry place so the plastic doesn't go bad. Chances are, if I don't use it again soon, I'll probably forget I have it, so it doesn't matter. An excellent tool for its price for its purpose.