Designed to meet the needs of ultra runners, the Mount to Coast R1 is a game-changer for tackling long distances. Built for performance and endurance, its ZeroSag insert is made with a proprietary compound that resists midsole compression over hundreds of miles. Plus, the innovative TUNEDFIT Dual Lacing System lets you customize fit separately for your forefoot and midfoot, while the wide toe box gives your feet room to breathe as the miles start adding up. Details: Upper: The double-layered jacquard upper made with 40% recycled polyester adapts to your foot while remaining breathable. The TUNEDFIT Dual Lacing System means you can adjust the forefoot and midfoot independently for a personalized fit that evolves with your run. Midsole: A combination of ZeroSag inserts and LightCELL foam creates the foundation for your longest adventures. ZeroSag, co-developed with BASF, maintains its cushioning properties even after hours on your feet, while the nitrogen-infused LightCELL foam delivers a ride that's 50% lighter than EVA with 45% more energy return. Lastly, the GOFLOW midsole geometry guides your stride naturally from heel to toe, helping you maintain that effortless flow state when fatigue starts creeping in. Outsole: a CPU outsole keeps the shoe exceptionally light weight while staying durable for the long haul.