The 3M PELTOR Alert Headset has been developed to help improve safety and motivation in noisy environments. It enables you to listen to FM-radio or external device (MP3-player, cell phone) and still hear your surroundings, or communicate with your colleagues without taking the hearing protector off. It helps safeguard you from harmful noise, while allowing you to work and interact with othersThe 3M PELTOR ALERT Headset helps protect you from potentially harmful workplace noise while at the same time provide the enjoyment of listening to the built in FM radio. The level dependent function for environmental listening allows sounds to be heard at a level below 82dB to increase your ability to communicate with nearby colleagues, as well as to hear warning signals, approaching vehicles, or sounds in machines and processes. The 3.5 mm listen only stereo input (limited to 82 dB) connects to external devices (e.g. mobile phone, two way radio, MP3 player) via the included 3.5 mm cable.