Built-in level-dependent function lets wearers hear ambient sound, such as conversation, machine sounds and warning signals. Wireless Bluetooth® connection to your mobile phone allows you to manage phone calls directly in the headset. Wireless Bluetooth®. Wireless Bluetooth® range up to 10 m (Class 2). Telephone calls can be managed simultaneously with a call on the communication radio. Integrated noise cancelling microphone. Automatically switches off after two hours of non-use to save batteries. 38 sub channels allow users to communicate individually using the same channel. Communication on 8 channels in the PMR 446MHz band.