These tail lights are perfect for that weld-on application.  Works great welded to a sissy bar molded to a frame or welded to a license bracket.

These dual function 1.25" LED's act as a brake light and running light. The size of the housing is 1 7/8"  diameter x 1" long.

Stainless or mild steel options are available. 

Will come with flat and dome lens.