3/8", Mist Auto Drain Valve, Use For Any Outdoor Mist Cooling System, For Installation To Thread It Into A 10/24 Female Threaded Nozzle Opening Or Insert It Into Any Professional Slip Lok Fitting, Use To Drain Water From The Mist Line When It Is Not In Use, Operates As A Siphon By Drawing The Water Out Of The System Once It Is No Longer Pressurized, When Installed At Low Points In The Mist Line, It Works With Gravity & Allows Water To Automatically Drain From The Line, This Reduces Nozzle Clogging & Prolongs The Life Of Your Mist System.