Building Materials and Construction Components Design Obsidian RBST Doorbell Panel by Serhat Apak & Burhan Özugur NETELSAN ObsidianRBST is a doorbell panel with video conversation. Functions carried on the bell panel are designed with modular architecture. Functioning modules 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. Design features allow use in all kind of grounds and environments including luxury buildings due to its elegant look and both inner and outer environments with its solid construction.