This low attenuating metal detectable earplug is ideal for use in the food manufacturing industry or where contamination needs to be considered. The 3M E-A-R Tracer 20 earplug contains a non ferrous Filter and has a fully metalised detectable cord in non-food blue, it is also moisture resistant, reusable and comes with a cord. Attenuation: SNR20dB, H25dB, M17dB, L10dB.