Ruggedly designed of soft, comfortable silicone, these reusable ear plugs are easy to insert in the ear, economical and offer protection comparable to many MSA ear muffs. Tri-Seal plugs (NRR - 25) are available in corded and uncorded versions in dispenser boxes of 100 individually packaged pairs. Also available in the corded version as one pair in a plastic case with a chain.