18KHz. Operating Temperature level: -20 ～ 50 ℃. Dimensions: 193x151.5 x292mm. Network Column Audio Speaker GEN-6191A03 Power Supply: DC24V/1A or POE. Interaction Procedure: TCP/IP, UDP, SIP. Signal-to-Noise Ratio: > 90dB. Frequency Action: 45Hz https://opticalnearme05813.popup-blog.com/29467834/how-an-ip-paging-system-improves-emergency-situation-solution-in-workplaces