Performance-oriented Mountain Running® shoes for ultra-long distances. Double BOA® rotary closure for quick and perfect volume adjustment, even while running. The same sole unit as the Jackal II, equipped with shock-absorbing Infi nitoo® technology, ensures less energy expenditure. Protective upper material with a precise, snug fit that provides stability even on the most technical sections of an ultra-marathon. Double closure flap made of 3-layer microfiber for support and flexibility. Double Boa® Fit System: maximum heel hold and optimal volume adjustment at the forefoot, as well as a technical fit for long distances. SpiralFit tongue and collar construction made of multi-layer, highly elastic Ariaprene protects against impacts and dirt ingress while ensuring high breathability. Innovative sole/outsole unit made of double-compressed EVA - one for cushioning and one for stability. The unit is equipped with Infi nitoo™ technology, featuring two internal shock-absorbing polyurethane pads with high energy return.