Union Pacific Dotted LED's have been made either by or for UP. Though they are mainly found on Union Pacific installations, they have also been seen on the AGR in Florida.

This LED is a typical design. They usually say "Union Pacific Railroad" in the center of the light. Not much is known about these LEDs since the manufacturer is not known, whether Union Pacific makes them or someone else makes them for UP.  They can be seen on almost any Union Pacific line, and are usually used to replaced incandescent lights at older crossings.  Sometimes, they've been used to replaced other LEDs too.

Some Union Pacific LEDs fade as well, while others don't.  Why this is I don't know, but it's neat to see at some crossings.