Yamaha 10-YVC1000-NA YVC-1000 - Speaker Phone - Wireless - Bluetooth - NFC - Black Multiple connection options via Bluetooth and USB Excellent scalability: daisy chains up to 5 microphones and supports 2 external speakers High quality audio technology with human voice activity detection (head) to minimize background noise during calls One-button auto tuning: analyzes room environment and automatically tunes acoustic settings to the optimal level