The Gamma MX Softshell Jacket is Arc'teryx' warmest Gamma, durable enough for the crag and weather-resistant enough for fast-changing mountain conditions. Alpine climbers and backcountry skiers can wear this midweight jacket alone in mild, mixed weather conditions, or they can wear this jacket as an insulating layer beneath a storm shell. Arc'teryx updated the Fortius fabric in this 2020 model to deliver a better warmth-to-weight ratio that climbers are sure to appreciate.