The allows you to use a standard 20-lb. backyard BBQ tank with your Forge 15 Grill. This tank has two hoses with independent valves and attaches directly to the back of each regulator on the Forge 15. Now you can grill longer and more economically using a standard BBQ propane tank. Two hoses with independent valves Attaches directly to the back of each regulator on the Forge 15 | HitchFire Propane Adapter Hose