Channel balance stamped "22 - 4 A"

Hello,

It looks like you have either our S351-23, with a 15-002 bottom attachment, or S390-23, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need. I'd also recommend double-checking the length of the metal channel since a 22-4 stamp (2240 spring strength option) would normally be for a 23" balance. 

Comparison of the S351 and S390 balance shoes.