28 inch channel balance

Can you show me the bottom fitting or attachment on these balances? We'll do our best to ID what you have from there. 

Thanks for getting back to me. This looks like an S770-28 with a 62-105 Hook attached on the bottom, which usually connects to a pivot shoe like the 15-208. We've seen this setup with Pennco windows before. We can custom make these balances with that hook attached for you. Our stamp ratings are a bit different than what your old balance used; we would use a stamp option of 28C for the balance, which means it would be meant to support a window sash in the weight range of 18 through 23 lbs. Does that seem right to you? Also, how many balances do you need? From there, I'll get a quote written up for you.