CAMCO AUTOMATIC CHANGEOVER TWO-STAGE REGULATOR - For RVÃ¢â‚¬â„¢s with dual propane tank hookup. Maintains constant gas pressure and automatically changes from empty tank to full one. Allows removal of empty cylinder for refill without interrupting propane supply. Inlet: 1/4Ã¢â‚¬Â SAE inverted flare. Outlet: 3/8Ã¢â‚¬Â NPT female. Ã¢â‚¬Â¢ CSA Approved. Double Stage Auto-change Regulator.