Old fashion technology; exceptional warmth and cushioning.
After we extract the very best bison down for the socks and gloves; use the second best short down for the bison felt hats and bison fiber rugs ... the leftovers ... the tough guard hair and scruffy really short down fibers are blended with some wool in a 50/50 felt ... and die cut into comfortable, cushioning warm felt insoles.
We are only making two sizes - Large and Xlarge - and two thicknesses - 4mm and 8mm - , as they are easily cut down to shape and size with regular scissors.
Takes up slack in shoes and boots. Cushions while it insulates.