Watts Retro 800M4-FR 1/2 in.-3/4 in. Freeze Protection Float Kit

This 1/2 to 3/4 inch retrofit pressure vacuum breaker repair kit for series 800M4-FR, which prevents the reverse flow of polluted water from entering into the potable water supply due to back siphonage. It consists of a float, spring, bonnet and bonnet O-ring.