éInnovating Thermal TechnologyAK80 boot liners offer durable cushioning and protection against extreme cold. These boot liners have Radiantex on the exterior to reflect the cold, and polypropylene with green polyethylene Volara foam to provide superior thermal insulation. AK80 boot liners are crafted in a "ski doo boot" style with heel reinforcements for extra support and are 8mm thick. AK80 boot liners suit a range of footwear, including: Sorel Boots, Columbia Stuttgart Hunting Boot, Columbia Midnight Hunting Boot, Itasca Swampwalker II Mens Insulated Boot, Columbia Willamette Hunting Boot, Proline Hidden Trail 2 Camo Boot, RedHead Bone-Dry Hobbs Creek, All Redhead Fishing Boots and White Creek Fishing Boots. To use our sizing chart: Measure your foot while wearing your socks. Then add 0.75" to both the width and the length of your foot to account for the stitching (e.g., if your foot is 4" wide and 11" long with your socks on, the measurements you would look for on the chart would be 4.75" wide and 11.75" long. This would give you a Liner Size of 11/12). Please note the sizing in the chart is approximate and may have a +/- 0.25" tolerance. Disclaimer: Please note that slight color variations among felt fibers may appear and do not indicate any defect or stain. Liner height is approximate. For a more accurate measurement of the liner height, please see the sizing chart. Custom cuts, densities and sizes are available upon request. If you require a special order, we can provide custom-made liners. The Felt Store has the capacity to manufacture boot liners of custom densities, cuts and sizes. Contact us today and one of our representatives will be happy to work with you to determine the best design to suit your needs.é