4 Pcs Anti Siphon Valve, Hose Bib Vacuum Breaker Set 3/4 Inch GHT Hose Backflow Preventer for Garden Spigot RV Hose Connection with Sealing Tape and Washers - Amazon.com
The Plumber's Choice 3/4 in. Hose Bib MIP/Sweat Connection 4 in. Anti-Siphon Sillcock Valve Frost Free Outdoor Wall Faucet with 1/2 in. SILLVAC4N - The Home Depot
SUNGATOR Anti Siphon Valve, Vacuum Breaker Set (12 Pcs), 3/4 Inch GHT Backflow Preventer Hose Bib Valve, Brass for Outdoor Faucet, Garden Spigot, RV, Anti-Backflow Hose Connector with Sealing Tape - Amazon.com
Orbit Hose Bib Anti-Siphon Valve 67750 - The Home Depot
6 Pcs Anti Siphon Valve, Hose Bib Vacuum Breaker Set 3/4 Inch GHT Hose Backflow Preventer for Garden Spigot RV Hose Connection with Sealing Tape and Washers - Amazon.com