Bilsom® Radio Hi-Visibility earmuffs feature a 3.5mm AUX input jack, allowing connection to MP3 players and other portable audio devices. Bright green earcups and reflective headband provide clear visibility, day or night. Radio Hi-Visibility uses patented Air Flow Control™ technology for NRR 25 when in the “off” position.Bacou-Dalloz Hearing Safety Group,, (800) 430-5490