I don't know why people are complaining about the puller. If you bend it you have to really try or push it against the edge of the rim instead of straightening it out. This is a thin rod or very thick wire. If it were much thicker it wouldn't fit through the valve hole in the rim. Don't pry, just push and pull at the right moment and everything will be perfect. I also don't understand why people say this set is difficult to use. It took me longer to get the parts out of the box (I didn't tear the bag) than to fix the valve stem. I needed to replace the rear wheel stem on my compact Kubota tractor. I put some dish soap on the extractor hood. Put it through the rim, turned it over and pulled out the old valve. (Just make sure you twist the hook on the puller toward the center of the valve, not where it catches on the rim.) I threaded the new valve stem onto the insertion tool and applied a fair amount of liquid dish soap to the end of the valve, and then push the valve to the edge of the insertion tool sleeve. Two light taps with a rubber mallet on the other end of the tool and the valve stem was in the rim. I stepped back to seat him, removed the instrument, and lifted the time. It took me less than a minute! Although I had to wait for the kit to arrive (2 days prime shipping) it was MUCH easier than jacking up the tractor, removing the tire (many bolts) and either taking it to a service center. Repair shop or circuit board breakage to replace the rod. Also, it can sometimes be difficult to reseal the bead, so with this set this is not necessary! This kit, some replacement valve stems, and a large bottle of Slime Flat Surface Repair Fluid are ideal for lawn mowers, small tractors, and ATVs. I will be keeping this quick valve replacement tool kit with my other emergency tools.