This LED light has the "double bullseye" design just like the marker/clearance lights on Airstreams from 1969 and many later models.

The light has a tough potted circuit board for total protection against moisture and vibration. They use a two-wire connection. Red is positive and black is ground. If your trailer uses a chassis ground for exterior lights (Airstreams typically use chassis ground), secure the black wire to your trailer shell using a mounting screw or separate hidden attachment behind the base.  You can do this by crimping a ring terminal to the wire, or simply wrapping it around the fastener.

If you are mounting this light in an aluminum casting on an Airstream, you may have to shave the base every so slightly on the top and bottom to fit some of the castings.  It can be done with sandpaper or a pocket knife. It will not be visible.

Details:

• Measures 4" x 2" and is 1" high at its highest point.
• Mounting holes are 3" on center.
• 10 LEDs per light.
• Rated to IP65, making it dust and water tight for heavy rain and road spray.
• White ABS base
• Amber or Red polycarbonate lens
• Two-wire connection.