Gascru Propane Refill Adapter - SAFEST Tank Fill Attachment - This Brass Regulator Valve Accessory Fits All 1 lb Cylinder Tanks - Lifetime Guarantee Built in safety feature that will ensure you NEVER over-fill your smaller tank. The Gascru adapter automatically cuts off gas flow when pressure is reached. Has Soft Nose POL (rubber ring allows for proper seal) 100% Solid Brass Construction makes it CORROSION RESISTANT . It pays for itself after only several uses.You'll never have to buy another tank again. Refill small propane cylinders for pennies in a minute.Lifetime replacement guarantee. Easily refill one pound bottles.Built Heavier, Bigger, and Safer than others on the Market.