Did this insole for a Superfit winter boots size 27, but one track is smaller. The insole in Gr. 27 measures 17.3 cm (Gr. 26 has 16.7 cm, Gr. 28 has 17.9 cm and fits into the boot) and is in the midfoot area slightly smaller than the original deposit. Looks neat processed from (edging round) .About the heat quality I can not say anything yet, because not used (above fluffy wool, aluminum layer below).