window balance

Hello there! Thanks for reaching out to us. I'm afraid the tape measure is obscuring the top and bottom fittings so I can't identify what you have here just yet. Can you show us a few close up shots of the top and bottom fittings? We'd also like to see a photo the inside of the metal channel where the innerspring connects to the pulley mechanism.

The metal channel should also measure 22". Can you confirm that for us? 

Thank you kindly for the additional photos. This looks like it may be the Series 351 or Series 390 channel balance with the 2010 stamp option. The best match will depend on the depth of the bottom shoe as shown in the image below. 

The length is odd though. If the balance is stamped 2010, the metal channel ought to measure 21". I'm afraid we can only offer a 20" length as our closest option though we can't promise a good fit. If you do decide to go with the 20" length you will have to weigh the window sash on a scale to determine the stamp option.

Comparison of the S351 and S390 balance shoes.