MSR ISOPRO Canister Fuel
MSR IsoPro is a performance-boosting, 80/20 blend of isobutane and propane, with the purest isobutane (5% or less n-butane) of any canister fuel. This clean-burning formulation maintains higher internal pressure at lower temperatures than standard butane/propane mixtures, delivering superior cold weather performance and more consistent output over the life of the canister. Available in 4 oz, 8 oz, or 16 oz canisters.
Propane mixes allows cartridges to maintain pressure at lower temps.