Synthetic-and-mesh Imported Rubber sole Trail Specific Outsole: Reversed lugs provide uphill and downhill traction on all types of terrain. Rearfoot GEL technology cushioning system: Attenuates shock during impact phase and allows for a smooth transition to midstance. AHAR Outsole: Acronym for ASICS High Abrasion Rubber. Placed in critical areas of the outsole for exceptional durability. Ortholite X-40 Sockliner: This premium sockliner features higher rebound properties while providing excellent moisture management and a high-level of breathability (Ortholite is a registered trademark of O2 Partners LLC.)