It does work as advertised. Watched it demonstrated at a local dealership a few yrs. back. Demo was a long board filled the length with nails. Motorcycle was run the full length and psi was checked afterwards. Air loss on both front and rear was only 2psi having several puncture wounds in tires. Majority of bike shops who mount and balance tires recommend it instead of wheal weights. I've had it in both front and rear now for some 3yrs. Balancing is superb! No puncture test as of yet. If doing yourself, remove valve stem, squeeze in 4oz. into each mounted tire, replace valve stem and air tire back up and go ride. At tire change time, dismount tire and just wipe out inside of tire with rag......only takes one wipe around inside of tire.