Easy Installation: Nolicated operations are required! Just simply remove three screws on top of the cap, then loosen the bonnet directly by hand and replace it with a new one. (Please make sure youve relieved all the water pressure in your system before you remove the bonnet.)Durable & Long Lifespan: The bonnet replacement is made of high-quality brass with precise CNC process manufacturing, which is durable, sturdy, impact-resistant, and corrosion-resistant while ensuring easy installation and removal. You dont have to worry about worrying about getting rust or damage during warm or cold weather.Long-Lasting Protection: Replace this upgraded version brass bonnet on your 720A to help you avoid a broken bonnet when the weather gets warm causing ice to thaw and leading to water leakage on the backflow preventer. Snug fit design can effectively provide long-lasting protection for your backflow preventer from the water back siphoning and back pressure into your drinking water supply.100% Satisfaction Guarantee: If you are not 100% satisfied with this check valve assembly repair kit, please simply return it for a full refund in 30 days. Premium Support & 12-Month Warranty. Package Includes: includes 1 x Repair Bonnet. Diameter: 2.1 inches.Perfect Fitment: This upgraded repair bonnet is designed to fit perfectly for a 1/2 to 1 Model 720A Pressure Vacuum Breaker (PVB). Exceed OEM standard replacement for 720A pressure vacuum circuit breakers/backflow preventers.