Sash Balancer?

Hello there. That stamp is not an identifier. It just tells us the strength of the balance. Please send us photos of the nylon attachments at both ends of the metal channel. That will narrow it down.

Thanks for getting back to me. This looks like either the S380-33 or S385-33 Channel Balance. The only difference between these two balances is the 'depth' of the bottom nylon shoe, or 'heel-to-toe' measurement. See below. Measure your old balance's shoe depth to see what matches best. For a stamp option, choose 3250.

Comparison of the S378, S380 and S385 balance shoes.