Performance is more than just a stiff flex rating. The Anthem 85 has the customizable features seen on our stiffer women's boots, like a heat moldable Powerlite Shell and GripWalk outsoles, but with a much more accommodating fit and feel. The end result is a user-friendly boot that delivers all-day comfort and impressive value. TECHNOLOGY: POWERLITE SHELL - K2's highest-performance shell design, utilizing shell walls of varying thicknesses and four different types of TPU to provide the ultimate combination of light weight and responsiveness POWERFUSE SPYNE - A rear co-injected "Y" shaped support that adds strength and power to the Energy Interlock in order to maximize fore/aft flex efficiency and lateral stiffness for responsiveness in every type of terrain LUXFIT PRO - pre-molded and Lasted with Ultralon heat moldable foams. Features an asymmetric tongue, pre molded ankle pockets, and a medium density collar & foam package yielding performance with added comfort ENERGY INTERLOCK - A rivet-free technology that integrates the cuff and shell, putting less stress on the boot's material and produces a smoother, progressive flex FASTFIT INSTEP - softer TPU material is used in the instep area of select models' shells for quick and easy entry and exit FULLY HEAT-MOLDABLE - Both the boot's shell and cuff are capable of being heat-molded to a variety of foot shapes for a true custom fit