ENL in SNAP for generating polarimetric matrices like C2

Where does SNAP fetch the information for ENL (or a multilook factor) while generating C2 matrices?
I ask so since there is no option of a user-defined ENL while generating polarimetric matrices like C2 here from the calibrated, TC complex image generated from ALOS-2 FBD 1.1 Data,

2020-05-30