For anyone that has the JDM tailights, it came with a gasket that goes behind the the housing. Theres two sets of these, anyone know how its suppose to go?

I figured a gasket to go from the housing against the body, but theres an extra pair.

Also my kit didn't come with a screw that holds down the cover that covers the led boards on the housing. Anyone know the size and thread?

Any help appreciated, thanks.