window balance

Question

It has the markings: 33 4 fv cmc 7

it measures 1/2 inch in width and 44 in length.

Bob · Accepted Answer

Thanks for posting. It looks like you have either the S351-34 or S390-34. The only difference between these two channel balances is the depth of the bottom nylon shoe, as shown below. In either case for a stamp option, choose 3340.

Comparison of the S351 and S390 balance shoes.