need a replacement

Hello, thank you for posting,

With this combination of attachments, you could have either an S380 or S385 channel balance. You’ll need to measure as shown below. The Series 380 has a 1" bottom attachment, and the Series 385 has a 1-3/32" attachment. 

I believe the stamp on your balance reads 29 9, which should correlate to a 30" balance channel excluding the nylon attachments. 

The stamp does not directly translate to the spring strength stamp option. You will need to obtain the weight of the window sash and compare to the strength chart on the product page. Please review and let us know if you have any additional questions! 

Comparison of the S380 and S385 balance shoes.