Window balance

Hello, thank you for posting,

It appears you have either our Series 351, with a 15-002 bottom attachment, or Series 390, with a 15-001 bottom attachment. Take a look at the image below to determine which balance you'll need.

You will need a 29" balance and based on the number stamped on the channel, a 2840 stamp option. This stamp can support a 23 to 28 lb window sash. I recommend removing the sash and weighing to confirm.

Please review and let us know if you have any additional questions. 

Comparison of the S351 and S390 balance shoes.