The 1¼”-2” Seat O-Ring is a vital sealing component designed for use in Zurn reduced pressure principle backflow preventers (model 975XL and 975XL2). Made from durable rubber, this O-ring forms a watertight seal between the check valve seat and the valve body, preventing leaks and ensuring reliable pressure retention. By maintaining a secure seal, it helps preserve the integrity of the check valve and protects potable water systems from potential backflow contamination.