If you work around engines, blowers, motors, vacuums, pumps, generators, compressors, or fans, you need protection against low-frequency noise - noise conventional passive earmuffs alone can’t handle. Only NoiseBuster Active Noise Reduction Safety Earmuffs combine high-performance passive with advanced noise cancellation technology to give the industry comprehensive hearing protection. For technical support call (203) 210-7230 or email sales@noisebuster.net.