Looking for correct window balance for 25 4 AX CMC 7

Thanks for writing in, Anil. This looks like it might be a S380-26 or S385-26 Channel Balance. The only difference between these two balances is the depth of the bottom nylon shoe, or the 'heel-to-toe' measurement. See the diagram below for reference. For a stamp option, choose 2540.

Comparison of the S380 and S385 balance shoes.