21" Window Balance 20-3 KX CMC 7 replacement

Question

I would like to purchase a replacement for my widow balance.  The white nylon slide on the bottom is broken.  I purchased a replacement for that part from you, but it didn't fit.  The metal channel is 21" long.  The stamp is 20-3 KX CMC 7

Casey · Accepted Answer

Hello,

Your channel balance resembles either our S351-21, with a 15-002 bottom attachment or S390-21, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need. Keep in mind that these balances have 1/2" wide metal channels. You'll also need 2030 spring strength options for your replacement balances. Thank you!

Comparison of the S351 and S390 balance shoes.