Can you help identify this

Hello there!

Thank you for reaching out to us. I'm afraid I don't recognize this top sash guide. I'm going to have one of our senior experts take a look and see if they could recommend a replacement for you. We'll reach out as soon as more information is available. Thank you!

We haven't been able to locate the source of your top sash guide, unfortunately. However, I wonder if the 18-203 might work as a substitute. Look over the dimensions and see how they compare with yours. 

Dimensions for 18-203