Balancer for Milgard non-tilting sash, 1/2" channel

Hey there. I am confident we can replace this channel balance; but first, can you show me the 'guts' or underside of the metal channel? Some balances from the west coast have a special design we must account for. Once we see whether or not that's the case here we can proceed.

Perfect, thanks. This looks like the S378-21, S380-21, or S385-21. The only difference between these three balances is the 'depth' of the bottom nylon shoe. See below. Measure your old shoe to see what matches best. In any case, for a stamp option choose 2030.

Comparison of the S378, S380 and S385 balance shoes.

My pleasure. Let us know if you have further questions, and thanks for reaching out.