"If you are looking for a solid freeride/all mountain boot packed with great features, then look no further than the K2 Pinnacle 130. FEATURES Synchro Interlock PowerFuse SpYne Replaceable DIN-Compatible Outsoles Padded Mid-Grip 45mm K2 PowerBuckle Integrated Tech Fittings Dual Cuff Alignment GLOSSARY PowerFuse SpYne A rear co-injected 'Y' shaped design that adds strength and power to the Energy Interlock, the PowerFuse SpYne maximizes fore/aft flex efficiency and lateral stiffness for sustained performance and responsiveness in all terrain. Because of the SpYne, we are able to optimize materials in the cuff and shell, eliminating excessive vibrations in rough terrain. PrecisionFit Tour INTUITION liner Our PrecisionFit Tour INTUITION' liner has the same high performance molded/lasted design features that give our all-mountain PrecisionFit INTUITION liner superior fit and ski performance, with the addition of Tour Flex Notches. These notches are strategically placed at the main hinge points, allowing the liner to flex naturally with the ankle and shell when in walk mode, improving range of motion and touring efficiency."