Do you carry these parts. If so, where in catalog. Does this one look familiar
A professional from anaheim, ca says:
April 12, 2021
Correction, it it attached to the top of the sash. It is a "sash cam". It holds the top of the sash balance in place.
Emily from SWISCO responded:
April 15, 2021
Your top sash guide looks very similar to our 18-008. Carefully look over its dimensions and compare them to your current hardware to confirm if this could work for you.