Yale Real Living Premium Digital Door Viewer with Internal Memory - View live images of who is at the door - Built in LED for assisted night viewing - Images stored in internal memory so you can see who called, even when you were out - External SD card can be inserted to extend memory - Includes 4 x AAA batteries - 105 degree viewing angle while not suffering from image distortion found in traditional door viewers - 3.2" LCD viewing screen provides large clear images of any visitor - Viewer screen can be seen from distances of several feet away - Simple installation, fits doors of (1.5in - 2.25in) thick - One Year Warranty for original owner - LED: Infrared LEDs for night mode - Door chime: 80db - Cylinder Drill Diameter: 0.55in - Dimesions, Viewer: 3.54in (H) 5.39in (W) 1.02in (D)