Usage: 1. Weigh the unused butane canister and write on the base with a marker. 2. Place the empty canister for about half an hour or overnight. 3. Take the canister out of the freezer and place the adapter on the canister. 4.Take your new full butane canister and insert it into the adaptor. 5. Press firmly on the bottom for 10-15 seconds and each time check the weight of the canister until it is equal to the original weight indicated on the base. With this adapter you can fill your canister of gas as if you were using a cigarette lighter. You save a lot of money when refilling the product. Notice: Once you have filled the canister, it is always advisable to check the seal of the canister to prevent leaks. Only fill your canister in a well-ventilated area, outdoors Please note: without gas tank. Lightweight: It weighs only 5g, so you can easily carry it when hiking and camping. Material: copper. Package Contents: 3*gas refill adapters.