caldwell 10 2 IR overall length is 11 and 3/4 with is 5/8

Hello,

With this combination of attachments, you could have either the S380 or S385 channel balance. You’ll need to measure as shown below. The Series 380 has a 1" bottom attachment, and the Series 385 has a 1-3/32" attachment. 

I'd recommend double-checking the length of the metal channel, which should be 11" without the end fittings. You'll also need 1020 spring strength options for your replacement balances. Thank you and let us know if you have any other questions or concerns.

Comparison of the S378, S380 and S385 balance shoes.