Channel balancer

Thanks for posting! Your balance appears to be either the S380-30 with a 1" shoe or the S385-30 with a 1-3/32" shoe. To determine which of these is the correct replacement, you'll need to confirm the dimension for the depth of your bottom shoe.

For the balances marked with a 29-4, you'll need to select the 2940 option. Unfortunately, I am not able to cross reference the 29-9 stamp. That said, to confirm the correct stamp you'll need to weigh the sash; there is a chart below the product description of the balances that lists the weight range each stamp can hold.

Comparison of the S380 and S385 balance shoes.