This is a set of optional parts for detailing ship models.
From the Hasegawa website:
Hunters on the wing
Japanese carrier aircraft were some of the most advanced planes in the world at the outset of WWII. The Zero was incredibly maneuverable and fast, its dive bombers were crewed by experienced pilots, and its torpedo bombers were equipped with weapons that, unlike American ones, consistently worked. In a war that came to be dominated by air power, Japan started out with the edge in naval aviation. Kit features three Type 52 Zeros, three type 21 Zeros, three "Jill" torpedo bombers, and three "Judy" bombers.