Check the listing for details. Birkenstock (All Sizes) Sport Blue Footbed Arch Support Insoles - Med Width. Condition: New with tags. Listed at 41.90 USD. Birkenstock Sport Blue Footbed Arch Support Insoles (Medium Width) The Birkenstock Blue Sport Footbed Arch Support Insoles are a 3/4-length, rigid orthotic arch support insole that provides a deep heel cup for natural cushioning and shock absorption, natural contoured arch support for longitudinal medial arch support, and a metatarsal support with a gentle raised platform for raising toes into the natural position. The Birkenstock Blue Sport Heeled Footbeds are ideal for a neutral to high foot arch type, shoes with heels up to 1 1/2 inches. They are constructed of Birkenstock's patented unique blend of natural cork lined BirkoCork, moleskine bottom, and a 73% cotton and 27% viscose synthetic fiber top cover.