Top sash guide??

Question

This is from the lower sash of a single hung non tilt window.   It is above the channel balance.  It keeps the channel balance from popping upward.   What part is it, please?

Bob · Accepted Answer

Thanks for posting. This looks a bit like the 18-174 Alenco Top Sash Guide, except in white. Please compare.

Detail of 18-174

Side view of 18-174