Have a 21" x 1/2" by your measurements window channel balance . There is also a 2040 indication .Problem I'm having is there is no match on your selection page to mine. The shoes are different bottom shoe looks like a
15-002 and top shoe looks like a
19-005. Wondering if a
series 380 or 385 would work because the only difference seems to be the extra guides on the sides or can you just make me what I have? They seem to be the originals. I have lived in this house for over ten years and have not replaced them and they were very new to the house when we moved in. I will need two of what ever works out. Thank you. Jason Z.