The 819M-FC-1.0V2 Fiber Adaptor is a FC fiber adapter that connects to a 1 inch port on a 819C or 819D Series integrating sphere. Flat Black coating is applied on the back side.  Flat black coating is to minimize the reflection from the back surface of the component back into the sphere, to simulate an open port. Comes with a 1.5 mm Allen wrench and M3 set screws.