Dual Cam Technology. The view offered by ordinary cameras is just too limited to provide complete protection. With a low-angle camera, blindspots are eliminated and your doorstep is in full view. 3-Second Preview Videos. See what triggered a recording, so you know how visitors approached your door and what they were doing. 2K with HDR. 2K HD surveillance ensures visitors can be identified from the details. And thanks to high dynamic range, visitors who are backlit by the sun can be seen in perfect color and clarity. No Monthly Fee. Access your recordings anytime on local storage without charge. No subscription fee required.   Note:1. Video Doorbell (Wired) S330 must connect to your existing wires.2. The power requirement is wiring with 16-24VAC, 30VA, or more. 3. If your transformer doesn't meet this standard, you'll need a new transformer to install your doorbell. Hire an electrician if you're unsure.