Doc's preformed earplugs are re-useable and made of soft, latex free plastic.  Proplugs are available in eight pre-molded sizes and fit 95% of the population.   Non-vented earplugs are used for medical applications to prevent water and high pitch sounds from entering the ear canal.  Vented earplugs are perfect for water sports to prevent cold water and wind from irritating the ear canal, prevents surfer's ear, and helps diver's to equalize easier.