Not sure what US firms would offer this Korean cup game but it's available in places like b365 etc.

Jeju are on a 5 game winning streak, playing some great football.
They are playing Sungnam, who are a top team but they have struggled recently.
Their 1st goalkeeper is on South Korea national team duty, and their back up keeper is nowhere near as good, which has led to their recent blip, and they've conceded 5 goals in their last 2.

Sungnam is still a dangerous team, good at home but with their recent form, and Jeju's excellent winning streak leads me to believe that Jeju are too big at those prices. They are the underdog for sure, but +400 is way too big for me!

worth a unit or two