Replacement Spiral Balances

Hello there!

Thank you for reaching out to us. It looks like you have a tilt window spiral balance. Depending on the diameter of the outer tube, the Series 900 (3/8") or Series 600 (5/8") would be my pick.

For a 19-1/2" tube, you can just round up to 20". That's what we've always done for these old 1/2" length tubes and we find that rounding up works fine.