RK1-720A - Rubber Repair Kit for 720A Pressure Vacuum Breakers, 1/2" to 1"Zurn RK1 720A Rubber Repair Kit for 720A Pressure Vacuum Breakers, 1 2" to 1" The Pressure Vacuum Breaker Repair Kit is compatible with the 1 2, 3 4, and 1 Model 720A Pressure Vacuum Breaker Assemblies. Repair Kit components come packaged with everything you need for easy repairs, including Bonnet Washer, Bonnet O Ring, Load Nut and Guide, Load Washer, Upper Disc, Poppet, Spring, Spider Screw, Lower Disc, Guide Spider and Hex Nut. Repair Kits are sold