Propane Auto Changeover Two-Stage Regulator with two 1/4" inverted female flare x 3/8" female pipe outlet. Most commonly used on RV's with dual tank hook-up. 11" W.C. setting. 1/2 PSI output. Automatically changes over from empty tank to full one. Can remove empty cylinder and take for refill without interruption. Gas gauge for monitoring pressure consistency through dual regulators.