The 4-Season Gas by Optimus keeps outdoor stoves running perfectly in all seasons. The high-quality gas mix consists of propane, butane, and an increased amount of isobutane, which features a particularly low boiling point. As a result, the 4-Season Gas delivers the same stable performance at near-freezing temperatures and high altitudes that users expect in milder conditions.

70% isobutane - 25% propane - 5% butane