Channel Ballance Replacement, Which One?

Question

I have 9 windows in my town house with broken channel balancers. I removed a set from one window and have attached the photos of each end and of the only marking available (UB 28D)

The channel (without end pieces) measures 29"

I'm hoping that you can tell me which i need to order from the information I've provided.
Much appreciated
Steve

User submitted image of their window hardware.

Paul · Accepted Answer

Hey, Steve. The balance manufacturer who made your hardware has gone out of business, but you should still be able to use our S380-29, which comes with a 19-005 top fitting and 15-005 (1" depth) bottom shoe. Please compare this hardware to yours to confirm. The spring weight option would be 2840.