Made from a soft rubber material, these plugs are easily cleaned and reused. Neck cord can be removed/replaced easily to accommodate users who prefer to use the plugs without the cord. These plugs come with a convenient carrying case for storage or the case can be attached directly to noise generating devices (eg. the handle of a lawnmower, etc.) to help keep the plugs clean and ready for their next use. Tested in accordance with ANSI S3.19-1974.