These 'Razor' Series Slim Muffs were engineered from the ground up with the goal of having the lowest possible profile, without compromising the hearing protection and amplification properties of the muff. Delivering an impressive Noise Reduction Rating (NRR) of 23dB, the Razor Series are sure to protect your hearing, without interfering. The Razor Series also feature Walker's new comfort fit headband for all day shooting and come in a host of color options. (Operates on 2 'AAA' batteries)