Please help me identify this window sash part

A home owner from Rockville Maryland (20850) says:
My rental property, a townhouse, was built in 1988. A few of my window sashes has this mysterious part, which I can't identify. I don't know the manufacture of the windows. I also went to Home Depot, but they could not help. This part closes the bottom sash's balance channel, much like a cap.

These are not tilt windows. The bottom sash can be lifted up.
User submitted photos of window hardware.
Profile picture of Tom
Tom from SWISCO responded:
Good morning! This appears to be something like our 18-124P. Please look them over and let me know if they match up.
A home owner from 20850 says:
Thank you very much. Yes, after some research and measuring, I also figured they must be 18-124P. I've already ordered these as well as the 371 balance channel.
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)