Lixada Safety POL Adapter Propane Refill Adapter Solid Brass Regulator Valve LPG Tank Refiller Canister Fill Coupler for 1LB Small Cylinders ( Item#: Y10641 )

This is fairly easy to use. The valve is nice to turn on and off if you are filling multiple bottles. If you freeze your empty bottle in the freezer before you attempt to fill it, you should be able to fill it to about 70% of it's original capacity. This is way better than buying these bottles and then throwing them away after just one use