18KHz. Intercom: Sustained, Integrated Microphone. Running Temperature level: -20 ～ 50 ℃. Dimensions: 283.1 * 224.3 * 269mm. Network Ceiling Audio Speaker GEN-6211A03 Power Supply: DC 24V/1A or POE. Interaction Methods: TCP/IP, UDP, SIP, ONVIF. Signal-to-Noise Proportion: > 80dB. Frequency Action: 100Hz https://communicationssystem39073.ttblogs.com/9551751/just-how-an-ip-paging-system-boosts-emergency-situation-response-in-workplaces