Window balance

Thanks for writing in! This window balance is a match for either the S351-33 or the S390-33. To determine the series you need, confirm the depth of the bottom shoe using the diagram below.

You'll need to look on the channel for a stamp/marking to determine the stamp option to select on the website. If the balances do not have stamps, you'll need to confirm the exact weight of the window sash. There is a chart below the product description that lists the ranges each stamp will support.

Comparison of the S351 and S390 balance shoes.