18KHz. Intercom: Sustained, Integrated Microphone. Operating Temperature: -20 ～ 50 ℃. Dimensions: 283.1 * 224.3 * 269mm. Network Ceiling Speaker GEN-6211A03 Power Supply: DC 24V/1A or POE. Interaction Procedures: TCP/IP, UDP, SIP, ONVIF. Signal-to-Noise Ratio: > 80dB. Frequency Feedback: 100Hz https://kameronemtut.blogrelation.com/36058698/enhance-your-interaction-with-an-advanced-ip-pa-system-today