Failure of old plastic top cap, need info

Question

My channel balances are popping up due to what appears to be failure of the plastic top cap.

I am interested in information needed and guidance available to help me choose the correct replacement part
Specifically can I replace only the plastic top cap....or does the entire unit need to be replaced

...information regarding installation, safety and qualified local repair services would also be helpful

Eric

A customer submitted photo of a broken top sash guide.

Tom · Accepted Answer

This looks like a piece broken off of a top sash guide. Can you please provide whatever dimensions you can? Seeing a picture of a whole guide--if available--would help, too.