Made of high quality materials, durable Female Cylinder Thread x Soft Nose P.O.L. For personal use. Fills 1 lb. Bottles in 1 minute or less as fast. It works with all 20, 30 or 40 pound 50, cylinders. With this adapter, you are not able to pour the smaller bottles that it will only put in the tank as much as it can hold, you can also refill the larger tank if you find yourself in a situation where your larger tank dries out. Connect the smaller cylinder with this adapter and equalize the pressure between the two tanks. Compared with others, ours has a safety function. When the flow capacity is too high, ours will automatically close at the end. This feature controls the propane transfer capacity and ensures that the tank never overflows. This protects you from dangerously filling the tank when there are none. For Tip Mounting:1, connect the left threaded adapter holder to the tank, connect the right threaded adapter cap to the 1 LB cylinder (tighten by hand)Turn the 1 LB cylinder and tank upside downOpen the valve on the tank for a few minutes until you hear propane transfer. Then turn off the valve. Return 1 LB of cylinder and tank to vertical position. First, disconnect the smaller 1 LB cylinder. Check the 1 LB cylinder for leaks: place a small amount of amp; frac12; Liquid soap and frac12; Water solution at the cylinder bore and relief valve. If