Watts Reduced Pressure Zone Backflow Preventer, Cast Iron, Watts 909 Series, Flanged Connection - 6 LF909-DOSY Drain Type - Off-line vent with supplies from below (A drain) and for easy filling

and for easy filling

its lip protrudes from the counter top surface by only 1/8 of an inch

The spindles are made of high-impact ABS plastic with a retractable pin outfitted with a concealed locking mechanism

If the wall is thinner

Watts Reduced Pressure Zone Backflow Preventer, Cast Iron, Watts 909 Series, Flanged Connection - 6 LF909-DOSY Drain Type - Off-line vent with supplies from below (A drain) and for easy fillingReduced Pressure Zone Backflow Preventer; Series: Watts 909; Size: 6 in; Connection: Flanged; Body Material: Cast Iron; Temp. Range: 33 Degrees to 110 Degrees F; Max. Temp.: 140 Degrees F; Max. Pressure: 175 psi; Width: 25 3 8 in; Length: 66 in; Standards: ASSE, AWWA, CSA, UPC, USC