Single hung 2640X

Thanks for your photos. Based on what I see here, you have either our S351-27 or S390-27, depending on the depth of the bottom shoe. That's the only difference between them. I recommend measuring your shoe and referring to our dimensions to confirm the best match.

Comparison of the S351 and S390 balance shoes.

Great! Yes, I agree. As long as your shoe is the larger 1-1/8" version then our S390-27 will be the part you want for this job. 

Please feel free to reach out if you had any other questions and I'd be happy to assist.