The Sidas 3Feet Eco Warm Mid insoles are insulating ski boot insoles for medium arches, built with a recycled felt top cover and an insulating foam that slows the cold coming up through the boot sole. Mid refers to the arch height, so these suit a standard, neutral foot.

• Mid arch height: the 3Feet system comes in Low, Mid and High shells, and Mid is the standard neutral arch.
• Built for cold: the insulating Evamic foam and thermal felt top cover are aimed at the cold that comes up through a ski boot sole.
• EVA shell: the moulded shell stabilises the heel and aligns the foot rather than sitting flat.
• Recycled content: the top cover is recycled polyester felt and the foam carries 20 percent recycled content.
• Lower footprint: Sidas state around 1.9 kg of CO2 per pair and contribute one euro per pair to the Sidas World Foundation.
• Sizes XS to XXL: covering roughly EU 35 to 48, with a two year guarantee.