Balancer for vertical sliding vinyl window

Thank you for reaching out to us. We're happy to help with this. We would just like to see an image of the inside of the balance’s metal channel, where the innerspring connects to the pulley mechanism; this connection is located in the middle of the channel. It looks like this balance is damaged so you will have to use an undamaged version as a reference. 

Thanks for the additional photos! The depth of the bottom shoe is measured as shown below. The last photo in your initial discussion post looks to be over 1", which likely points to the S385-26 with the 2530 stamp option. Take a look at the specifications and let us know if you have any questions. 

Please note that the metal channel should measure 26" long.

Comparison of the S378, S380 and S385 balance shoes.