Window Part

Hello,

It's tough to be sure while it is still installed but your pivot shoe resembles the 15-015. The determining factor would be how the width and thickness below compare to yours.

Dimensions for 15-015

If it's a match, this pivot shoe is commonly used with the 5/8" diameter S600 spiral balance. You'll need to confirm that your housing tube measures exactly 23" not including the plastic tip or spiral. There is a chart under the product description that will help you choose the correct color option based on the weight of the window sash that the balances support. Thanks for posting! 

How to measure the tube width of a spiral balance.

How to measure the tube length of the S600 spiral balance.