HIKVISION 2MP Dome with inbuilt Mic
 
2 MP coaxial audio camera[MAKE SURE YOU HAVE iDS SERIES DVR]
Enhancing safety with a discreet and economical built-in microphone
Transmits audio over the coaxial cable
EXIR 2.0: advanced infrared technology with 20 m IR distance
4 in 1 (4 signals switchable TVI/AHD/CVI/CVBS)