The 3M E·A·Rsoft Metal Detectable earplugs are made from slow expanding polyurethane foam material, that gives evenly distributed pressure allowing flexibility and a good seal with optimum comfort.With the advantages of the E·A·Rsoft with the added benefits of a blue detectable cord and an integral stainless steel ball in the non-food blue earplug. Ideal for use in food manufacturing industries. SNR 36dB H=34dB, M=34dB, L=31dB