100008 Oboz Thermal Trail Insole Cold feet can ruin a perfect day on the trail. Oboz's new Thermal Trail Insole has all the comfort and protection of the Trail Hike Insole, with the addition of Solarcore thermal insulation. Developed for NASA, Solarcore's Aerogel technology uses trapped air to provide unparalleled thermal performance. Best for Winter Oboz's anatomically-designed insole maximizes stability and support with a medium arch and deep cushioning heel cup Sizing XXS: W's US shoe size 5.5 - 6.5 XS: W's US shoe size 7 - 8 S: W's US shoe size 8.5 - 9.5 / M's US shoe sizes 7 - 8 M: W's US shoe size 10 - 11 / M's US shoe sizes 8.5 - 9.5 L: W's US shoe size 11.5 - 12.5 / M's US shoe sizes 10 - 11 XL: M's US shoe sizes 11.5 - 12.5 XXL: M's US shoe sizes 13 - 14