COSTA LOOP RETAINER: The Costa Loop retainer is a minimal retainer designed for sunglasses with larger temple holes. The molded center clasp separates to thread through the end loops for secure, all day hold. From end-to-end, the Costa Loop Retainer measures 20". The Costa Loop Retainer is compatible with all Costa sunglasses. VISIT THE COSTA BRAND SHOP: Click on the Costa logo above to view the entire Costa sunglasses and accessories assortment.