18" channel 5/8" wide

Thanks for posting. This looks like either our S380-18 or S385-18. The only difference between these two channel balances is the depth of the bottom nylon shoe, or the measurement from 'heel-to-toe'. See the illustration below for reference. Compare both with your old balance to see what matches best. In either case for a stamp option go with 1730. And yes, generally when one balance breaks, the other isn't far behind--nor does it work well to pair a new balance with an old one, since it will just cause the new one to wear out faster. Therefore replacing both is usually the best way to go. Let us know if you have further questions.

Comparison of the S380 and S385 balance shoes.

Great to hear, Patrick! Let us know if you have any other questions, thanks for reaching out, and happy holidays.