Bob from SWISCO responded:
January 22, 2019
Thanks for posting. Take a look at either our S351-37 or S390-37 Channel Balances. The only difference between these two balances is the 'depth' of the bottom nylon shoe. The Series 351 bottom nylon shoe has a depth of 1", whereas the Series 390 bottom nylon shoe has a depth of 1-1/8". Compare with your old balances and see what you think matches best. Once you have determined which balance to select, you must choose a stamp option. Your stamped number of 3640 corresponds to a window sash weight range of 23 to 30 lbs. If you are uncertain this is correct, you can always weigh your window sash to make sure it fits within this weight range. Let us know if you have any questions. |