Costa Fathom Cord: The Costa Fathom Cord is a Marine grade, soft nylon cord retainer with adjustable logo bead and slip fit attachments to ensure your sunglasses stay put, on and off the water. From end-to-end, the Costa Fathom Cord measures 28". The CostaFathom Cord is designed to fit most styles with co-injected temples. Born on the water in 1983: Costa Sunglasses for men and women is celebrating 40 years of making the premium sunglasses on the planet and protecting the watery world we call home