spiral balance

I have a spiral balance that is 28" in length by 3/8" in diameter. It has a red tip and the spring end has two 1/8 diameter roll pins that are separated by a measurement of 1/2" center to center. Each roll pin is 1/4" in length and is attached through the end of the spiral balance.

I need the replacement part number so I ensure that I am ordering correctly.

Thanks so much,

Steve