Earmuff Sonic 540 Headband

- Built-in lithium-ion battery - Up to 55 hours in use - Up to 100 hours standby - Built-in microphone for conversations in low-noise environments - Simple controls with glove-friendly buttons - SPT (Sound Protection Technology) limits sound in the speakers to a safe level of no more than 82 dB - Automatically power off after 4 hours of inactivity - Adjustable headband with soft, replaceable head cushion - USB charging cable included - Noise-cancelling boom microphone available as an accessory for conversations in noisy environments