The Thin Blue Line (USA)decals are printed on a high quality reflective material which includes an 1/8" border surrounding the state flag design. The 2.25" x 4" rectangular decals have a self-adhesive backing for easy application on the exterior of a car, motorcycle or any other smooth surface. The Thin Blue Line Flag originated in the United Kingdom: the blue line represents law enforcement, the black field on the top represents the public while the black field on the bottom represents the criminals.The idea behind the graphic is that law enforcement (the blue line) is what stands between the violence and the would-be victims of crime.The Thin Blue Line USA flag incorporates the American flag into the Thin Blue Line concept.