window balance

Hey Lydia. This looks like either an S380-23 or S385-23 Channel Balance. The only difference between these two balances is the 'depth' of the bottom nylon shoe, or the 'heel-to-toe' measurement. See the diagram below for reference. Compare both balances with your old hardware to see what matches best.

Comparison of the S378, S380 and S385 balance shoes.

You then have to choose a stamp option, which reflects the strength of the balance. Your old balance's stamp is a little unusual. To know which one to pick, weigh the window sash that these balances support. We can then match that exact weight with one of the weight ranges listed alongside each stamp option on either balance's shop page.

Prices are listed on the shop pages for both the S380-23 and S385-23. Let us know if you have further questions.