For noise levels up to 105 dBA, these cap attached with double-shell technology to provide effective hearing protection. Proprietary Twin-Cup™ design has soft, foam-filled earmuffs. Easy cap-mount design. Earcup pivot points that tilt for optimum comfort and efficiency. Liquid/foam filled earmuff cushions. Colour-coding to help match attenuation needs. NRR: 27 dB. CSA Class AL.