If you own a pressure washer, you need a cache of O-rings somewhere in your garage. Preferably you'll have a nice organized set of them, but if not, this kit will work just fine. This is a collection of some of the most common O-Rings you'll find in a pressure washer—specifically, the ones AR makes. So, if you ever encounter a leak or perhaps you are rebuilding a pump, and you run into a damaged O-Ring, you know you have some on hand.