Originally Posted by rkkwan
My seat 57D on 74J B-HOR 4 days ago has the large single 1/4"-type plug connector.
Okay, maybe the 747 is different from the B777 they fly regionally. Sorry it's been a while since I flew in Y on a 747. Best for OP to take both the 2 pin and the 1/4" plug connector... just in case.