REVO America R164D3GT5GM21-4TFC 16-Channel 4TB DVR Surveillance System with Eight 700TVL 100-Feet Night Vision Cameras, 21.5-Inch Monitor and Free Bonus Covert Camera (Black) Cameras have a built in microphone for audio monitoring capability View and access live and recorded video remotely over the internet or mobile phone LED lighting distance: max 100ft Hard Drive: 4TB Connection type: 12 RJ12 and 4 BNC ports