Mavic Ksyrium Elite II Road Shoes Energy Carbon Comp outsole has a composite fiberglass and nylon insert with carbon reinforcement for maximum stiffness Light, rigid and thin 6mm outsole with low 7.5mm stack height brings the foot closer to the pedal for improved energy transfer Ergo Fit 3D+Ortholite is a dual density insole designed with OrthoLite foam and heel and arch EVA support, providing excellent foot hold and stability for optimal energy transfer OrthoLite foam with 3D ergonomic construction manages moisture, plus it's lightweight, breathable, antimicrobial and environmentally friendly Endofit Tongue with Salomon fit technology closely hugs the foot in key zones for maximum comfort