Background Trimming (Oval) Description
A flag blue oval-shaped embroidered device 1 3/8 inches (3.49 cm) in height and 2 1/4 inches (5.72 cm) in width with an inner lemon yellow oval 5/8 inch (1.58 cm) in height and 1 1/2 inches (3.81 cm) in width.  All edged with a 1/8 inch (.32 cm) flag blue border.

History
The background trimming was approved on 18 December 2007.

Source: The US Army Institute of Heraldry