Spiral Balance Replacement

Thanks for posting. When you measure the diameter, are you measuring the spring or the outer tube? The balance in your picture is actually missing its outer tube, so if you're only measuring the spring I see here then it will not be accurate. I would check to see if you have an old balance that still has its tube and measure that. Then again, if the inner spring is 3/8", then there's a good chance your tube is 5/8" in diameter. If that's the case then I would recommend our Series 600 spiral balance.

Your tip color is also a little outdated, so you will need to weigh your sash on a scale to determine the proper option.