5000 Series 4mm High Top Boot, Round Toe Plush Thermal Lining Plush insulation that retains heat and wicks away moisture. Horizontal Velcro cinches Glued and Blindstitched (GBL) seams N-Grip Sole Neoprene layer for comfort and N-Grip outer sole to give the natural bare-foot feel required for direct contact with the board. Achilles Cushion Molded ankle pads for improved comfort and support in the ankle area. Heel-Hold Box Giving support to the heel / ankle area and preventing the boot from rolling on the foot. Apex-Flex neoprene Bamboo Charcoal inner sole Bamboo Charcoal is best known for its inherent antimicrobial and anti-odor properties, but few are aware of the Far Infrared Ray (FIR) reflecting ability of this unique material. The fabric reflects the body’s FIRs back to the wearer, resulting in reduced fatigue, quicker warm-up time and improved regeneration. This natural fiber is woven into our bootie lining.