Birkenstock - Birko Contact Sport Insoles - BlueBirko Contact Sport insoles are a full length, semi rigid orthotic arch support insole for low to neutral arch types. They feature a microfiber lined foam top layer with a deep heel cup for natural cushioning and shock absorption, natural contoured arch support for longitudinal medial arch support, and a low impact metatarsal support. The EVA base provides flexibility and also helps absorb shock while molding to your feet over time for superior