Window channel balance
Hello there!
Thanks for reaching out to us. We don't sell a shoe like this. It looks like yours may be broken which would account for the "ramp". Can you confirm that for us? It would also be a great help if we could see a photo of a shoe from the balance on the other side of the window, or an identical window.
That's a very odd style of shoe, we've never seen anything like it. However, you're welcome to purchase the Series 380 and then reuse your old shoe. We have a video tutorial regarding how to replace the fittings which I will post below.
Based on the 28B stamp, you may need the 2820 stamp option for your replacements. A pair of balances with this stamp will support a sash weighing 12 to 16 pounds.