Channel Balance 2890

If the depth of the bottom nylon shoe is 1", use the S380-29. If it is 1-3/32", use the S385-29. In either case, the spring weight for 2890 10 will be 2830, for a window sash weighing between 16-23 lbs.

I did notice an odd cylinder part at the bottom of your nylon shoe. We've never seen that before. Is this common to each balance you need to replace? Do you know if it's important for the balance's function? Consider this before going ahead with either the S380-29 or S385-29. 

Do you know what purpose the magnet functions? We honestly have never seen anything like that before, and it certainly shouldn't have any critical role in the function of a channel balance. Otherwise your balance resembles either the S380-29 or S385-29.