Background Trimming (Oval) Description
On a black oval-shaped embroidered item with a 1/8 inch (.32cm) white border, 1 3/8 inches (3.49cm) in height and 2 1/4 inches (5.72cm) in width overall, a yellow diagonal band from upper left to lower right bearing three scarlet stripes.

History
The Background trimming was approved on 12 Oct 1995.

Source: The US Army Institute of Heraldry