Viking single hung balance springs.

Thanks for writing in. See our S380-27 and S385-27. The only difference between these two balances is the 'depth' of the bottom nylon shoe, so compare both with your old hardware to see what matches best. You'll need to select a stamp option. Look for a stamp code on the metal channel that corresponds to one of our stamp options. If there is none or you are uncertain, get the exact weight of your window sash, and match that exact weight with one of the weight ranges listed alongside each stamp option on the product page.