3M PELTOR WS ALERT X Headset is a Bluetooth headset with noise-cancelling boom microphone that connects to your mobile phone for hands free calls and streaming in noisy environments. The headset has a level-dependent function for ambient listening, and it syncs to a mobile app so users can easily set-up and adjust the headset, Attenuating hearing protector comes in two models: headband or a safety helmet attachment (MRX21P3E4WS6), Bluetooth technology for connection to an external Bluetooth device allows for hands-free talking and streaming, Noise-cancelling boom microphone for clear speech transmission in noisy environments, Level-dependent function for ambient listening to help promote auditory situational awareness, Connection to an iOS and Android compatible mobile app, 3M Connected Equipment, to more easily set-up and adjust the headset. The app is available to download from App Store and Google Play. Mobile app allows you to receive reminders when to change replacement cushions (