What is the midlength version? Looking on Operation Parts site there is either carbine, medium, and long. So is the medium the midlength?
I didn’t know KAC made a mid length version…DD, Larue, Troy, MI all do. What exactly are you looking for?
They make a “medium” version which is 10.375" long, a tad shorter than their “medium” URX II (10.75").
It won’t work as a “mid-length” handguard per se with a mid-length gas system and FSB but would work great on barrels 11.5" or longer (with carbine or mid gas and a low-profile gas block).