Professional noise-canceling headsetHD Full-Duplex sound transmission with integrated SBC codecAdvanced Noise Control: active noise suppressionLarge 32mm speakers with 7.1mm thicknessBoom microphone length: 160mmHearing protection: NRR (ANSI S3.19 1974 US) 21dBFM Radio: Supports 76-108MHz frequencies and stores up to 10 preset stationsBluetooth Intercom Network: Supports up to 4 simultaneous connections per groupBluetooth Intercom Range: Up to 800m in open terrainBluetooth 4.1: Pairing with smartphones to receive calls and play musicMulti-channel intercom compatibility