The Quick Products QP-BOPCP Blow Out Plug Combo Pack includes the Quick Products QP-BOPQCB Blow Out Plug With Brass Quick Connect and Quick Products QP-QCBPGF Quick Connect Air Compressor Irrigation Blow Out Fitting - Female. Clear your RV water lines quickly and easily with the Quick Products Blow Out Plug. Any water left in the lines over the winter months may freeze or dilute your antifreeze, which can lead to leaking and burst pipes. The Blow Out Plug attaches to your RV's city water inlet to allow the attachment of an oil-free air compressor to blow out any remaining water. Simply open the faucets, attach the air compressor and watch all the water leave your water lines. (Note: Do not exceed 50 PSI from the air compressor when clearing the lines.) Connection size: 3/4"-11 NH. The Quick Connect Air Compressor Irrigation Blow Out Fitting from Quick Products allows for an easy winterization of your underground irrigation system, stopping freeze damage from water left in the pipes and hoses. The female fitting attaches to the blow out valve and accepts common quick connect air compressor fittings. The one-piece construction and interior rubber gasket eliminate any potential leaks due to cracks and seams, providing a tight, reliable seal every use. Be sure to follow the blow out instructions provided by the irrigation system's manufacturer and wear ANSI-approved eye protection during use.