Zekler Sonic 550 is a hearing protector with wireless quality sound without compromises on the protection. Add a noise-canceling boom microphone for phone calls in noisy environments, level-dependent listening and long battery life, and you have all the freedom you need for a comfortable and safe working day. Boom microphone with advanced noise reduction for clear and distinct communication even in the event of loud noise. Level-dependent listening technology that amplifies faint sounds and lets you hear ambient sounds while being protected from loud impulse sounds. Easy operation with hand-friendly control buttons Play, pause, next, previous, answer / reject incoming call, end call, volume up / down, phone assistance (eg Siri, Google assistant) SPT (Sound Protection Technology) limits the sound in the speakers to safe levels at max 82dB. Built-in lithium-ion battery provides up to 55 hours and 100 hours of standby on one charge, charged via USBAutomatic shutdown after 4 hours of inactivity to save the battery if you forgot to turn off the cover. Adjustable headband with soft, replaceable headrestBluetooth USB charging cable included Complies with PPE Directive 89/686 EEC, PPE Regulation 2016/425, EN 352-1, EN 352-8 and RED 2014/53 / EU. Attenuation values H = 32 M = 26 L = 17 SNR = 29