Window sash balance

Please have a look at both our S351-30 and S390-30 channel balance. The only difference with these two balances is the depth measurements of the bottom balance shoe. The depth measurement of the bottom shoe for the Series 351 is 1" and for the Series 390 is 1-1/8". You will need to measure the depth of your bottom shoe, like in the diagram below, to determine which balance is the better match. Whichever one chosen will go with the 2920 option.