The Auto-Changeover LP Regulator allows you to hook up to 2 Propane tanks. The regulator automatically switches over to the second tank once the first one runs out (and vice versa). The indicator changes color to let you know when a tank has been depleted and needs to be refilled. The inlet is a 1/4" SAE inverted flare, and the outlet is a 3/8" NPT female pipe thread; rated for 345,200 BTU. Compatible with Flame King's 48-inch Thermo Plastic Hose (Model 100383-48) and 12-18 inch INVERTED FLARE Pigtails (Models E12INPT, E15INPT, or E18INPT). Note: NPT pigtails are not recommended.For your safety and to ensure leak-free performance, these regulators are assembled using high-strength thread-locker (Loctite) on the adapter connections where the pigtails are attached. This is an intentional safety measure designed to keep critical fittings secure and prevent gas leaks during use. Material: Steel.