Razor Slim Electronic Quad Muff Black including Bluetooth syncs with mobile devices. Features integrated communication mic with four hi gain Omni directional microphones. Low noise/frequency tuned for natural sound clarity and you can control the volume. NRR 22 sound activated compress with 0.02 second reaction time. Muff has comfort headband with metal wire frame with a compact folding design. Bluetooth Sync with mobile devices with integrated communication mic Ultra low profile ear cups with four hi gain Omni directional microphones Low noise / frequency tuned for natural sound clarity with sound damping compression housing Sound activated compression 0.02 seconds reaction time with a NRR22 Comfort headband w/metal frame recessed volume control knob