The only reason it is not a 5 is that there is no recess on the bottom for the wiring or connectors. You have to raise it off the mounting surface somehow to fit in the crimped barrels if you cannot stuff the wires back into wherever you are mounting it and line that up with the end of the fixture where the wires come out.
Extending the side plastic to make a skirt and create a recess under the light would make this a GREAT product. Another option would be to provide a gasket of a complimentary color to provide for the same recess.
Where I mounted the two lights I installed was not very visible so I just snugged down the front and left the rear of the fixture elevated. If the wife complains I will seal around the fixture with silicone and be done with it.
Replaced two flourescent in our yacht's saloon with two of these. The white light is brighter and better for reading etc. The red is great to give those below an excellent light at night when night vision retention is essential. A very versatile light. We will buy another for the head and perhaps one for the master cabin too.
Aqua Signal lists the dimensions of this light incorrectly. The lamp is 16"L x 3.125"W (NOT 4.45"). Was trying to replace an old lamp and needed to cover a fairly large hole in the cabin ceiling. The slim width is problematic for my application. Otherwise this seems to be great lamp with the red/white options. White seems to be fairly bright too.