Need 2 spring replacement for my single hung window

Thanks for your photos. Based on what I see here, you have either our S380-24, S385-24, or S378-24 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.

If your sash weighs 31 pounds, you can use the 2365 stamp option. This is designed to carry 30 through 34 pounds.

Comparison of the S378, S380 and S385 balance shoes.