This seems to

This is an old rod-type balance. They haven't made these in a long time, but the good news is that you can use a more modern style channel balance to replace it.

Your next step should be to measure the diameter of the spring. If it's 1/2", then you can use our Series 795 as a replacement. The video below covers exactly how to install these in your window, step-by-step.

If your spring is 3/8" instead then come back here and let me know. It will be a little trickier but still absolutely doable.