18KHz. Operating Temperature level: -10 ～ 55 ℃. Measurements: 296x140x130mm. Network Audio Bridge GEN-3101A01 Power Supply: POE. Communication Method: TCP/IP, UDP, SIP. Signal-to-Noise Ratio: > 85dB. Frequency Reaction: 50Hz https://marcodxixi.blog4youth.com/30524403/improve-your-announcements-with-a-top-quality-ip-paging-microphone