There is a plastic piece that spans the front of the roof from corner molding to corner molding on all the OEM appearance lights. My H3 came with it already installed. It's actually more of a pain than anything else. It makes a lot of wind noise at speeds over 70mph.

 

The plastic piece is what the 3 middle lights are mounted to. It allows you to easily wire the 3 middle lights & the 2 end lights, without having to pop holes for wiring thru the roof in 5 places and having to pull the head liner to run wiring. The kit wiring runs up the driver's side A pillar between the A pillar plastic trim and the actual A pillar then underneath the middle plastic piece and above the roof, over to the passenger's side A pillar light.

These 5 lights on ebay are JUST the lights. The FULL lighting kit would contain the 2 end lights, the 3 middle lights mounted to the plastic piece, the drilling template for mounting, wiring instructions and hardware.

Note that the 3 middle lights are designed to mount to the plastic piece and they may not match the contour of the roof which has a different contour than the plastic piece.