31" Channel Balances Needed

Thanks for writing in. This looks like either an S351-31 or S390-31. The only difference between these two balances is the 'depth' of the bottom nylon shoe, so compare both with your old hardware to see what matches best. 

In general, we always advise you replace the original stamp option. So for instance, for a balance stamped 30-3, this would correspond to our stamp option of 3030, which is for a window sash in the weight range of 16 through 23 lbs. If you are uncertain, weigh the window sash. Obtain that exact weight, then match it with one of the weight ranges listed alongside each stamp option. See below:

Stamp Option Sash Weight Range

3010      7 to 12 lbs

3020    12 to 16 lbs

3030    16 to 23 lbs

3040    23 to 28 lbs

3050    28 to 32 lbs

3060    32 to 35 lbs