These LED lights have the "double bullseye" design just like the marker/clearance lights on Airstreams from 1969 and many later models.
10 LEDs per light. Tough potted circuit board for total protection against moisture and vibration. Positive lead wire off back of base. Ground through one of the two mounting screws.
If you are mounting this light in an aluminum casting on an Airstream, you may have to shave the base slightly on the top and bottom to fit some of the castings.