WCH Second Generation L.E.D.'s have been around since 2000 and have not been very popular until early 2008. Union Pacific has been known to use this kind of LED on their newer crossings, and CSX has been a major user since 2008.

The differences between the first and second generation L.E.D.'s are that the 2nd Generation are more of a rounder type than the first generation. 2nd, there are flashing sidelights on the 2nd Generation and the 1st Generation does not.

One common thing with a lot of dotted LEDs, but especially this one, is they cause camcorders to make it look like they are flickering, which is not actually happening.  I'm not sure why they do this, but it is noticeable in the video down below.

Model number of this kind of L.E.D is 985-811.