The Plumber's Choice 4 in. Anti-Siphon Sillcock Frost Free Outdoor Faucet with 1/2 in. MIP/Sweat Connection and 3/4 in. Hose Bib SILLVAC4 - The Home Depot
How to Install a Frost-Proof Faucet Outdoors (DIY) | Family Handyman
Woodford Model 17 8-in L x 1/2-in Copper Sweat Brass Anti-Siphon Push/Pull Sillcock in the Sillcocks & Hose Bibbs department at Lowes.com