Allows for recording Audio with your CCTV security system. Your DVR must have Audio input feature (most do). Mic only. 
 
Specifications:
Plug and Play
Extremely Sensitive
Great for Security Monitoring
Higher S/N Rati
Range : 150 Square meters
Audio Output: RCA Female
Sensitivity : 200mA/ubar
Work current : 5 mA-60mA
Work Voltage: DC12V
Frequency: 200-6000HZ
Max output Voltage: 5V-upp