28" Channel Balance

Hi- thanks for posting! 

I was able to narrow what you have down to two options. You either have our Series 351 or our Series 390 channel balance. The difference between these two balances lies in the depth of the bottom shoe. The Series 351 has our 15-002 shoe which measures 1” deep and our Series 390 which has our 15-001 shoe and measures 1-1/8”. These measurements are depicted in the photo below. Please compare your measurements to the information that I provided and let us know what you think.

Comparison of 15-001 & 15-002

Once you determine the correct series, you'll want to select the 28" length in that series. The 27 B typically does correlate with the 2720 option, but to be sure we always recommend you weigh your sash and refer to the sash weight range chart. 

Hi there! 

Based on your measurements it sounds like you have our S390-28 with the 1-1/8" shoe, and that yours has just worn down a bit over time. In regards to your sash weight- in my first response I recommended the 2720 option based on your stamping, but based on the weight of your sash (15 lbs.) I would recommend choosing the 2730 option. It's possible the wrong balances were installed originally. Let me know if you have any more questions.