The Five Ten Camp Four has a Nubuck leather upper & a Stealth C4/S1 combination outsole. Its moulded PU external heel cage adds support & stability, while the lace-to-toe closure can be worn relaxed for a long distance fit, or tightened for climbing & scrambling. Glossary: Nubuck:A type of leather with a soft, velvety surface that is far more durable than suede. Stealth C4:A rubber sole used by many top climbers that provides excellent edging & high friction. Stealth S1: Durable high-friction rubber absorbs far more shock than traditional rubber outsoles.