Meet the EQUES Digital Door Peephole Viewer: a handy solution that lets you see who is at your door. It has a big monitor for you to watch the outside. There is also a built-in doorbell button and adjustable volume settings. The device turns off when there is nobody outside to save energy.
You can use this to take photos or record video to a 32 GB memory card. When the doorbell button is pressed, the device automatically takes a photo or video. The EQUES Digital Door Peephole Viewer kit has a wireless design. Not too expensive either.