Koss Koss QZ77 Active Noise Reduction Ear Plug System

FeaturesReduces harmful and annoying low frequency sounds in noisy environments.Specialty ear cushion material forms slowly in ear canal providing a custom fit and maximum isolation.Dynamic stereo phone element for extended frequency response - 10 - 20,000Hz.Compact design for convenient travel and portability.Ideal for in-flight use.Unique ear bud design directs sound into the ear canal for deep bass and extended frequency response.