Maximum 33 dB attenuation is ensured when you use these pre-shaped foam ear plugs. The smooth, soil-resistant outer skin prevents dirt from penetrating the surface prior to insertion. Individually wrapped by pairs in poly bags. Polyurethane foam enhances comfort, especially for long-term wear Bell shape delivers maximum in-ear comfort Contoured design easier to insert, resists the tendency to back-out of the ear canal Smooth, soil-resistant closed cell-foam skin prevents dirt build-up Bulk refills for Leight® Source 400 and Leight® Source 500 earplug dispensers save time, waste, and space