Need replacement sash balance

Hello, thank you for writing in! We would be happy to help you find replacement channel balances. The stamp that you indicate tells us the necessary spring strength, but we will still need to determine what series you have. In order to do this we will need to see clear images of the plastic fittings at either end of the channel. I would preferably like to see them from above with the open side of the channel, where the spring is revealed, facing up. Thanks!