this is a very ridgid Glazing Bead
A quick learner from Denver colorado says:
January 13, 2015
need this Glazing bead identified with part numbers
Dave from SWISCO responded:
January 15, 2015
Take a look at our 55-164 glazing bead. It is not the same dimensions, and not as rigid as the one shown in your photo, but it may still work. Take a look at see what you think. If not, see if you can get a name off the window to identify the manufacturer, maybe we can find something better then. Thanks!