Flag of the La Unión Department.
(Used a low-quality image as a base for the image, so was not able to correctly create the image.)

Based on: https://en.wikipedia.org/wiki/File:Bandera_del_Departamento_de_La_Union_ES.jpg
https://en.wikipedia.org/wiki/File:Bandera_del_Departamento_de_La_Union_ES.jpg
Flagvisioner