... , intercom & chimes 3. Built-in memory, 2.4 inch screen Features:1. 4-in-1 security door viewer,built-in digital camera, color display, intercom ... pixel Screen Size (W x H) 49 x 36.7 mm (2.4 in diagonal) Camera Color CMOS sensor, 0.3M pixel ... ) Operation Humidity 10 - 90% Door Thickness 25-65 mm (1-2.5 in) 4-in-1 security digital video door viewer with color display