18KHz. Intercom: Supported, Built-in Microphone. Running Temperature: -20 ～ 50 ℃. Measurements: 283.1 * 224.3 * 269mm. Network Ceiling Audio Speaker GEN-6211A03 Power Supply: DC 24V/1A or POE. Communication Protocols: TCP/IP, UDP, SIP, ONVIF. Signal-to-Noise Ratio: > 80dB. Regularity Action: 100Hz https://bestbluetoothspeaker44343.bloggosite.com/36523477/spon-communications-leading-the-way-in-cutting-edge-ip-pa-system-designs