"Over-the-head 3M High-Visibility earmuffs feature double-shell technology to provide effective hearing protection. Twin-Cup design has soft, liquid/foam-filled ear cushions to minimize resonance and block out maximum high and low frequencies. Stainless steel headband distributes weight for low-pressure fit. Battery Required No, Case Included No, Disposable No, For Noise Levels Up To dB 105, Adjustable Fit Yes, AM/FM Radio No, Pairs qty. 1, Noise Reduction Rating NRR dB 30, Hearing Protector Type Earmuffs. Earcup pivot points tilt for optimum comfort and efficiency Hi-vis Green color for workers in low light conditions For noise levels up to 105dB NRR 30dB, the highest NRR for any earmuff tested by an accredited lab Meets ANSI S3.19-1974"