Sash guide for channel balance, black, metal, flat part is top of sash, hook part on side of window facing jamb of window frame.

Thanks for reaching out to us. This appears to be a top sash guide of some kind, but not a style I've ever seen before. Would you happen to know who made your window?

In the meantime, we'll look into this and see what we can hunt down for you.

I'm sorry to say that I've run into some problems finding this guide. It has a very unique design and nothing I find is quite the same. I'll need detailed, written measurements before we can proceed.

To start, I need the width of the base and cap, as well as the length of the while guide. I'll also need the hole placement from the top down; make sure to measure from the center of the hole, not its edge. Finally, please provide the depth of the top cap and the depth of the base NOT counting hook.

Please make sure that these dimensions are as precise as possible and that they're written down for us to review. A photo of a tape measure won't help us in this case. Thank you!