18KHz. Running Temperature: -20 to 50 ° C. Capacities: φ213 x 165mm. Network Wall Mount Speaker GEN-6011A03 Power Supply: DC24V/1A or POE. Interaction Protocol: TCP/IP, UDP, SIP, ONVIF. Signal-to-Noise Ratio: > 80dB. Regularity Feedback: 100Hz https://speakers04702.blogofchange.com/30484402/improve-your-announcements-with-a-high-quality-ip-paging-microphone