Main Features: Filling Butane Canister Adapter for Hiking Camping Stove The Gas Filling Adapter is equipped with spare o-rings to install inside the copper tube Made by high-quality copper material, which is durable for a long time use Small size and lightweight, you can carry it very conveniently With the gas adapter, you can conveniently fill the gas canister, which will save you money by filling. Directions: Weigh the unused full butane canister and write with the felt tip on the base. Place the empty refill container in the freezer for approx. Half an hour or overnight. Remove the container from the freezer and place the adapter on the canister. Take a new full butane canister and insert it into the adapter. Push the canister firmly down for 10-15 seconds at a time, checking the weight of the canister each time until it matches the original weight stored under the canister Warning: For safety reasons, the weight of the refill canister should be lighter than the original canister! Once the container is filled, it is always good safety practice to check the seal on the canister for leaks! Only fill the canisters in a well-ventilated area, i.e. in the open air! Specification: Material: Copper Size: 11x1 0mm/0.43x0.39" Top Diameter: 3mm/0.12" Bottom Diameter: 8mm/0.31in Note: Please allow 0.5-2cm differences due to the measurement