What Spiral Balance Is This?

I am confident we can replace these spiral balances, but the only way to know for sure which you need is to confirm the length and diameter of the outer tube, up to and not including the colored tip. From there we'll do our best to narrow this down for you. Thanks. 

If the length of the outer tube, up to and not included the colored tip, is 14", then you're going to need either an S900-14 or S600-14. Which one depends on the diameter of the outer tube; whether it is 3/8" or 5/8". I suspect your balance has a 5/8" tube diameter, because the blue tip is only seen with the Series 600. Therefore you'd likely need an S600-14. But double-check this to be certain.