Canister stoves are one of the simplest types of stoves available, beaten only by alcohol and solid fuel stoves. Canister stoves use pre-packaged canisters filled with a pressurized mixture of propane and butane. When the canister is connected to a stove, the vapors from the liquid reach the burner and are ignited. Canister stoves require no priming, only a spark or a flame in the emitted vapors. Due to butane being a part of the mixture, canisters are able to have lower pressure and are therefore much lighter than if propane was used alone. Unfortunately, this means that cold greatly affects the usefulness of canister stoves. Regular butane mixes stop working below zero, while the more common isobutane works down to the 20s (Heid).