... . Accessories: Base flange, DIY tightening tool, Peephole, Barrel&Lens.16. Inner-contain: two pcs AA batteries( it can ... in anti-theft door consists of two concave and convex lens. When seeing outside from inside door, the image ... outside will fall on the lens and finally get a bigger image. But because ... of lens, it is easy to be peeped.3. Digital ...