Stamp 1620KA

Hey there,

Thanks for writing in!  Your channel balances are either the S351-17 with a 1" shoe or the S390-17 with a 1-1/8" shoe. 

To determine which series is needed for your window, look over the dimensions from the diagram below to confirm the depth of your bottom shoe. You'll need to select the 1620 stamp for a sash weighing 8 to 12lbs.

Comparison of the S351 and S390 balance shoes.