It builts in microphone and loudspeaker .

It supports full-duplex speech, real-time video, and automatic infrared night vision.

The resolution of camera is 720*576p.

Type: Doorbells
Brand Name: Cleverdog
Model Number: DOG-Doorbell
Power Source: Battery
Doorbell Type: Wireless
color: orange, blue,gray, pink option,and we send Blue at default
Lens: Color HD camera lens, 110° wide-angle
Video: H.264,720x576 @15fps
Voice: Inside Microphone and loudspeaker
WiFi network: Support
Wireless standard: Station, Access Point, and Wi-Fi Direct
Wireless protocol: 802.11b, 802.11g,, 802.11n
Security: WPA&WPS 2.0
Power: Micro USB,input 5V -----500mA
Power supply model: Lithium battery,2500mAH