Replacement balances
Thanks for posting! Your channel balances appear to be either the Series 351 Channel Balance with a 1" shoe or the Series 390 Channel Balance 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 17" balance from the list of balances in one of the links above, once you've confirmed the series. This balance will use the 1620 stamp option.
For the longer balance you'll need to confirm the length of the balance and then check the metal channel for the appropriate stamp option.