Replacement balance

Hello! I can't totally tell... do you have winged tabs on both the top and the bottom plastic parts? I see them on the bottom, clearly, but I'm not sure about the top. If the attachment on top has wings, this will be a Series 380 or a Series 385 balance. You'd then measure the bottom shoe to tell which of the two. The difference is the depth: Series 380 uses a 1" shoe and Series 385 uses a 1-3/32" shoe.

Then, measure your metal bar. Your "28A" might be equivalent to a SWISCO "2810." 2810 requires a 29" metal bar, so if your metal bar is 29", you can choose the S380-29 or S385-29 balance.

From there, consider a 2810 stamp option if your window weighs 7 to 12 pounds.

So, what I said before stands. This is a Series 380 or Series 385 balance. It's impossible to tell which one by sight. You need to measure the shoe yourself like this: