These are the flap hinges. There are 4 hinges per flap. Scuff the area to be glued. The skinned area of the flap will need to be marked and notched out where the hing slides in so it can be glued to the ply area of the the flap.You will want to put the hinges on the actual flaps first. You will line up the bottom edge of the glued area of the hinge with the bottom profile of the flap and fully forward. It does not need to be right up against the wing skin. You can have about a 1/32" gap from the bottom and front of the flap skin. Next, you will put the hinges in the flap wells after you line them up where you want the flaps. You can put each pair of hinges together with the bolt and locknut to line everything up better.

The real A10 has big gaps where the flaps meet the wing area. Dont be alarmed when you see the gap when you begin to align them, it was just me trying to make it look more scale. Just space them evenly.