Noren Aerogel Insole is a trekking boot insole made for the coldest winter days in the outdoors. The materials have been specifically chosen and combined to crossbreed a very comfortable and cushioning footbed with a record low conductivity thermal insulator and thus shield your feet from deep frozen terrain and help keep them warm. Noren was made to stand up to the tough requirements placed on our winter trekking shell boot Skare Expedition, and will fit all of Lundhags trekking shell boots and many other shoes and boots. Top layer of warming wool Midlayer of super low conductivity thermal insulator Primaloft Aerogel Cushioning and support from highly breathable Arneflex XMAX ECO foam MaterialsPrimaloft Aerogel. 70% wool, 30% polyester, open cell Polyurethane foam