A Silver color metal and enamel device 1 1/8 inches (2.86 cm) in height overall consisting of a shield blazoned: Vert, between two laurel branches in base a torch Argent, enflamed Tenné, detailed and fimbriated of the second. The shield is ensigned with a Mustang's head couped at the neck also Argent (base metal). Attached below the shield a Green scroll turned Silver and inscribed "McARTHUR" in base metal letters.
Orange, green and white are the school colors. The laurel branches symbolize achievement in all school endeavors. The torch and flame symbolize excellence in academic pursuits. The Mustang head alludes to the school's tradition of riding a horse onto the football field. The school's mascot is the "Mustang."
The shoulder loop insignia was authorized 2 November 2004.