ObsidianRBST a doorbell panel with video conversation. Functions carried on the bell panel are designed with modular architecture. The camera, screen, speakers and microphone, keypad, card reader are each separate functioning modules and can be used with various alternatives depending on the project requirements. "Functional modules" with the aluminum extrusion profile, create the body of the product and there are LED wall washers lighting on both sides of the ObsidianRBST. With its metallic appearance on both sides of the product, aluminum extrusion profile gives a robust, durable and simple impression while enhancing the mechanical durability of the product against outer factors and impacts. Function modules consist of an injection molding of plastic parts. Modules have interconnectors therefore mounting of the product to the site of use (field) is easier and takes shorter than its alternatives. Black and metallic color exhibits an appealing image in many different environments and makes it suitable for crowded business centers, residences, skyscrapers and even for farm houses.