Oboz's anatomically-designed trim to fit thermal insole maximizes stability and support while reducing heat loss to keep your feet happy on-and-off the trail when the temperatures drop.Material: PORON Comfort pods, medium and high density EVA, reflective mylar base layer, polyester thermal moisture-wicking comfort top layer with antimicrobial odor controlArch Height: MediumWeight: 1.6oz (M9 1/2 pair)