Design: The Walkers Razor Slim electronic muffs with its ultra-compact design, offer superior hearing protection in a low-profile design Sound Activated Compression: Sound activated compression has a blazing fast 0.02 second reaction time to ensure your hearing is always protected Hearing Protection: The Walkers Razor Slim Electronic Muff offers a noise reduction rating (NRR) of 23 dB, effectively protecting your hearing from loud noises Microphones: Two hi-gain omnidirectional microphones pick up outside noise and broadcast it through full dynamic range HD speakers for an ultra-clear, balanced sound Bundle Includes: Walkers Razor Slim Let Freedom Ring Electric Earmuffs with Cushioned Ear Cups, Built-In Speakers, and Walker's Crosshair Sport Shooting Glasses (Clear)