A contractor from Denver Colorado says:
September 21, 2015
I have 2 types of bead here. I'm not sure what type they are one is for a window and one is for a sliding glass door.
Paul from SWISCO responded:
September 22, 2015
Take a look at our 55-192 glazing bead. I think this looks like a good match but just make sure our measurements are the same as yours.