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.
- Two Sizes: Sold in 4 and 8 oz. canisters to meet the demands of any stove or trip. The 4 oz. canister is sized to fit inside the 1.0L Reactor® Stove System.
- Improved Performance: 80/20 blend of isobutane and propane delivers superior performance throughout the life of the canister and in colder temperatures.
- Clean-Burning: Zero-maintenance combustion.
- Fuel Gauge: Built-in float gauge determines how much fuel is left (4 oz. and 8 oz. canisters).
- Recyclable: Consult your local recycling center for regulations.
At first Penberthy set out to meet this challenge under a committee of The Mountaineers. He spent more than eighteen months testing stove fuels, the elongation of ropes, the holding power of pitons, the strength of ice axes and a whole list of other important but generally neglected issues. As time went on, the scope of the project stretched far beyond what the organization, and Penberthy, could afford.
MSR began in 1969 as a newsletter committed to improving mountaineering safety. Our founder, Larry Penberthy, was an engineer, professional inventor and lifelong mountaineer who dedicated himself to making the backcountry safer.
