A clean-burning fuel for high-performance backpacking stoves, the MSR IsoPro Fuel Canister delivers more consistent performance than standard butane/propane mixtures at any temperature. Designed to boost the performance of your backpack stove, this 80/20 blend of isobutane and propane utilizes an extremely pure isobutane (5% or less n-butane). This special formulation maintains higher internal pressure at lower temperatures for better performance over the entire life of the canister. Clean-burning formula for less stove maintenance. Built-in float gauge (in 8-oz. canisters). Clean-burning fuel for high-performance backpacking stoves 80/20 blend of isobutane and propane with extremely pure isobutane Maintains higher internal pressure at lower temperatures for better performance Clean-burning formula - less stove maintenance Built-in float gauge (in 8-oz. canisters)