Quick Connect RV, Brass Blow Out Plug, Completely Clear Your Water Lines, Screw The Plug Into The City Water Inlet, Open All Drains & Faucets, Attach & Activate The Air Pump Until All Lines Are Clear, Patented, Helps Clear The Water Lines In Your RV During Winterization & De-Winterization, Built With Brass, Screws Into RV City Water Inlet, Heavy Duty, Makes Winterizing Your RV Easy.