The DH-DS21 Wireless Chime is an indoor standalone doorbell that rings when your outdoor video doorbell is pressed. The DH-DS21 can be paired with Dahua’s LincX2PRO DHI-DB11 or DH-DB6I doorbells. With the DMSS application, you can customize your chimes, making your security system not only functional but also personalized. For added convenience, the DH-DS21 Wireless Chime can be linked to multiple video doorbells at the same time, ensuring you never miss a visitor no matter where you are in your home. The 5MP WiFi Video Doorbell is a component of the Dahua LincX2PRO residential series. The doorbell offers specialized motion detection that distinguishes humans from other objects and transmits video and audio to a mobile device for remote visual confirmation and communication with visitors. This device is compatible with Dahua NVRs; Dahua X5, X7, and X82 Series HDCVI DVRs, and with the DMSS application.