Mr. Heater Stay-A-While Tee Excess Flow Soft Nose P.O.L. x 1 inch -20 Male Throwaway Cylinder Thread x Female P.O.L. with Acme Thread x .25 inch Inverted Female Flare Connects auxiliary propane cylinder to motor home and additional appliance Solid Brass Construction Has brass nipple to open safety valve in male throwaway clylinders Has rubber gasket for sealing