The Doorbird DS101 is a smart home surveillance system that includes a POE Injector for power supply. This device allows users to monitor their home or office remotely through a smartphone or tablet. The POE Injector ensures that the Doorbird DS101 is always powered on, even if the power goes out. With features such as two-way audio, video recording, and motion detection, the Doorbird DS101 provides added security and convenience for homeowners.