18KHz. Running Temperature level: -10 ～ 50 ℃. Dimensions: 440x300x44mm. Area Mixing Digital Amplifier NBS-2301 Power Supply ： AC 220V, 50Hz. Power ： 130W ， 260W ， 360W ， 550W ， 700W. Interaction Protocol ： HTTP, TCP/IP, UDP, ARP, ICMP, IGMP. Signal-to-Noise Proportion ：. Mic Input 01: ≥ 65dB,. Mic https://cashbbxsg.newsbloger.com/30544421/the-duty-of-an-ip-paging-microphone-in-effective-work-environment-interaction