If you have pneumatic tires on your mower, wheelbarrow, pressure washer, etc., you need them! Every spring and once or twice every summer I had to top up the tires on my gardening tools. It was extra work that wasted my time. I finally thought enough of this nonsense and went in search of something to stop the leak. I chose Flat Out because it should stop leaks up to half an inch. While other brands claimed only a quarter of an inch. I've put it on every air tire and so far no tire has lost air in the last two years.