Cairn 3D features a zero-drop anatomically molded footbed, with tasteful arch and toe support. Built for those seeking extra support or looking to log big miles. Vibram® XS Trek Regolith Outsole: Lightweight, long-lasting, and re-soulable. Our most durable Vibram® outsole compound, best for grip in Dry conditions. For more performance grip in wet + slippery terrain consider the Cairn Pro lineup.