Description Use the existing door without breaking the door structure without the need of drilling, no wiring and installation can be used. The product is equipped with intelligent operating system and user-friendly design. It is easy for old and children to use, to protect your family security. Features: 3.5 inch color screen display, see the image of visitors clearly. Wide-angle lens: see everything outside at a 120 degree view. Low consumption and high resolution. It provides an extra security and convenience for you and your family. Easy to use: short press to turn on, long press to turn off. 24 hours monitoring with high definition color image sensor. Specification: Condition: 100% Brand New Resolution: 480 x 320 Power Supply: 4 * AAA batteries (Not Included) LCD Screen: 3.5" Door Hole Range: 14-28mm Door Thickness: 40-100mm Indoor Device Size: Approx. 12 x 6.2 x 1.8cm / 4.7 x 2.4 x 0.7" Outdoor Diameter: Approx. 3.2cm / 1.3" Package Weight: 196g Package Included: 1 x Outdoor Unit 1 x Indoor Unit 1 x Screws Set 1 x User Manual . Note:Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. This product does not have a doorbell dialogue function, it is only used for viewing the situation outside the door.