Window channel balance needs replacement

Hello,

If the metal channel measures 16" long, you could have either the S351-16, with a 15-002 bottom attachment, or S390-16, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need. 

You'll also need to weigh your sash to determine which option you'll need. There is a chart on the product page that explains how to choose your option based on the sash weight. 

Comparison of the S351 and S390 balance shoes.