Hi, This is from an aluminum frame thermo-pane single hung window circa 1980. I have been told it's an Andersen #230 but can't verify that. It connects to a spring.
Thanks, Ernie
Paul from SWISCO responded:
September 10, 2019
Hello, Ernie. Our 17-059 sash balance bracket looks almost exact to your part. Look it over and let us know if you agree.