Replacement balancer for milgard window.
Thanks for posting. This looks like either an S380-27 or S385-27. The only difference between these two balances is the depth of the bottom nylon shoe, or the measurement from heel-to-toe. See the diagram below for reference. Compare both balances with your old hardware to see what matches best. For a new stamp option choose 2650.
Apologies, let me clarify. For any new balance, you have to choose a stamp option. This designates the strength of the balance, or the weight range it can support. Your old balance was stamped 26-5. This conforms to the S385-27 stamp option of 2650, which denotes a balance that can support a window sash in the weight range of 26 through 30 pounds. Let me know if that makes sense, or if you have other questions.
Glad I can be of help, and to you as well.