Hello, This is a corner piece for a window frame. Windows are double glazed aluminium.
Paul from SWISCO responded:
September 21, 2017
Hi from SWISCO.com. Please have a look at our 18-091 Kawneer top sash guide. Compare its measurements to yours and let us know what you think.
A quick learner from Massachusetts says:
September 21, 2017
Thanks. I found it earlier and have 10 on the way. Measurements seem close so I chanced it. Thanks for the help. I'll update again if they aren't the right piece.