The isoSeek IV is a dirt loving animal built for your next trail adventure. A stable trail shoe that's at home on gnarly trails, the isoSeek IV features excellent forefoot cushioning with a 1:1 Energy Cell, and smooth, graduated guidance with the 1:1 Guidance System. 1:1 Seamless Upper creates an unparalleled fit with a seam free interior. 1:1 360 Lacing anatomically conforms to the foot for a tailored fit regardless of foot shape. 1:1 Graduated Guidance System guides the foot from heel strike to toe off for a smooth, consistent feel. 1:1 Energy Cell cushions the forefoot upon impact and then returns energy back to the runner as it compresses and rebounds on contact.