Super Viton o-rings are high performance o-rings that stand up to the stresses of pressure washer applications. They have a high chemical resistance keeping them from deteriorating over time from chemical contact. They also have a very high heat resistance. Other standard O-rings can melt out of a hot water machine in seconds, these super vitons hold up great against the heat! Try super viton O-rings in your pressure washer couplers… you might be surprised at the difference!