SAFETY - Built-in safety feature helps prevent over-filling of smaller tanks. Durable, heavy-duty design for reliable performance. Automatically cuts off gas flow when pressure is reached. Rubber ring ensures a proper seal. EASY INSTALL - No additional tools required. Features a hand-tight grip for secure installation. CORROSION RESISTANT - Constructed from 100% solid brass for a secure, airtight connection. GREAT FOR - Camping, tailgating, outdoor heating, outdoor cooking, and other outdoor applications. Enables refilling of 16 oz and 1 lb propane tanks from larger propane tanks. REFILL EASILY - Compatible with all refillable green 1 lb propane cylinders. Allows for quick and easy refilling. INSTRUCTIONS: **CAUTION** Due to the flammable nature of propane, refilling must be done outdoors. Keep away from flames, sparks, and ignition sources. For best results, place the empty 1 lb cylinder in the freezer for up to 30 minutes before refilling. Attach the adapter to a 5 lb to 50 lb propane tank. Connect the chilled 1 lb cylinder to the adapter. Carefully turn the larger tank upside down and secure it in place. Open the valve on the large tank and close it when liquid propane flow stops. Return all components to upright position and disconnect the 1 lb cylinder. Repeat as needed. NOTE: The bulk tank must be inverted to allow liquid propane to flow. Empty cylinders should be chilled to reduce vapor pressure for effective transfer. Refilled cylinders are not filled to 100% capacity. This is intentional to allow for safe expansion and prevent over-pressurization in warm conditions.