Did you know that one pound propane cylinders costs about three times more per pound than the 20 lb. tanks that fuel your barbeque grill? Did you know more than 30 million "disposable" propane cylinders get thrown into landfills each year? The MacCoupler is a money-saver for anyone who uses a 1 lb. propane cylinder but doesn't want to spend money replacing them. Now you can safely and easily refill 1 pound propane cylinders with the MacCoupler Simply attach the MacCoupler to your 20 lb. tank, then attach the 1 lb. cylinder you want to refill, and in less than a minute your cylinder is filled and ready for use. Save yourself money, and prevent unneeded waste! (See instructions and safety warning with product).