The Birkenstock Mayari thong sandal is a distinctive classic model with a toe loop and cross strap. The combination of anatomically shaped footbed and secure adjustable instep strap makes Mayari extremely wearable in a wide range of situations. Classic support and adjustability, designed beautifully. A Legendary DesignThe core of all models is the original Birkenstock footbed. The construction helps your feet feel as comfortable as possible for hours on end Interior & Exterior Arch SupportThe arch support that run alongside the sides of the footbed surround the tarsal bones inside and out. This gives the foot the stability it needs when it takes a step. Deep Heel CupThe very deep molding in the heel area supports the foot tissues and holds the heel bone firmly in its natural position. This provides the foot with nearly as much support when it is in a sandal as when it is in a closed shoe.