26 6 EW CMC 10

Thanks for posting. This looks like it might be either the S380-27 or S385-27 Channel balance. The only difference between these two balances is the 'depth' of the bottom nylon shoe, as shown below. Measure your old balance's shoe depth to see what matches best. In either case choose 2660 as a stamp option.

Comparison of the S378, S380 and S385 balance shoes.