Per Febco 905-052 Kit Riparazione Gruppo Valvola di Ritegno 1/2 3/4 765 GBV PVB Backflow
(It is for use to repair check valve on 1/2" & 3/4" model 765. 1) Series 765 Pressure Vacuum Breakers are designed to be installed to provide protection against back siphonage of toxic or non-toxic liquids.