Yale digital door viewer with internal memory this ingenious solution to home security is ideal for seeing and storing images of who comes and goes from your house whether it39s unwanted visitors cold callers or nosey neighbours you can keep track of who is at your door and now you can save the images too the door viewer camera is designed to fit a 14mm hole for a standard optical door viewer designed for doors with a thickness of 38 to 100mm and a viewing angle of 105 degrees th