30 an 36 inch window
A quick learner from CA says:
October 10, 2016
the attached are pictures of the counter balance that was in a 30 inch window. I need a pair of these and also a pair of balances for a 36 inch window, same style, that doesn't have the old balances in the windows, so I can't look at them. I need both sets of replacement balances. My guess is the 30 inch window is ~25 lb's and the 36 inch window 35 lb's.
Tom from SWISCO responded:
October 13, 2016
Please see our Series 385 channel balance, this appears to match what's in your pictures. I do not recommend estimating sash weight, it's always best to weigh on a scale to be sure.
For the length of the balance for the 36 window, you may want to go with a 34" long balance.