Footprint Gamechanger Insoles are recommended for people with low/fallen arches/flat feet with pre existing joint pains or people with mid arches who want serious protection and added balance. This is the ultimate joint support. The low 3.5mm model is thinner than the standard Gamechangers and are designed for lower profile shoes such as dress shoes, running shoes, cycling cleats etc. Footprint Gamechanger’s are a custom Heat moldable orthotic. Heating activates our proprietary arch technology which causes the insole to expand and shape to your unique foot. They are covered from heel to toe with Artificial Cartilage foam which absorbs up to 90% of impact energy. The world's best performing most advanced orthotic is also surprisingly simple to mould. A special urethane foam formulation re-cures with heat. Simply warming the insole will cause the inner arch to react and rise, then it can be easily moulded to the foot. As it cools down it will take the specific shape of the arch and become firm in your specific arch shape, giving you real custom orthotic support. Full instructions are detailed on the packaging.