I have never used this method but have read about this kit here at Revain and THANK YOU for all the helpful people and feedback. I noticed my daughter's tires were very low and insisted she help me find and fix the problem as it was her car. We jacked it up, made a thick soap solution and inspected the entire tire. Guess where was the problem? It was a workshop repair patch that leaked! this. no nail, just gum in previous nail hole. Her eyes saw very small bubbles. made from a thick soapy solution. I also pierced the inner patch with a stretching tool and reamed the hole completely to size. Use pliers to pry the "plug" out of the lot and push the end to get it through the needle. Unable to insert the uncoated stopper on all sides, the needle and stopper with attached bath were then pushed in to 1/2 inch with great force. Inflated the tire to 45psi (51 max), sawed off the extra 1/2 inch and applied liquid soap to the area to check for blisters and there weren't any!