Everbilt 1/2 in. x 12 in. Brass MPT x MHT Anti-Siphon Sillcock Valve

Everbilt anti-siphon frost proof sillcock assure protection against freezing and undesirable back siphoning. Because they're frost proof, they can stop outside hydrants from freezing and bursting the pipes. Plus, the anti-siphon feature protects against water siphoning back to contaminate the potable water system. Also, unlike anti-siphon attachments, which must be manually drained to prevent freezing, the integral anti-siphon design is self-draining.