- Solid colored t-shirts are 100% combed ringspun cotton, however, heathered colors could contain a cotton/polyester blend
- Preshrunk to minimize shrinkage
- Double-needle sleeve and bottom hems
The 3rd Radio Researchd Unit (Detachment) were among the earliest U.S. military advisors in Vietnam;
3rd RRU later grew to become the 509th Radio Research Group
These occupations, which required a top secret clearance with Special Intelligence/crypto special clearances,
were essential to U.S. Cold War efforts. ASA units usually operated in four groups using revolving shifts to provide
coverage twenty-four hours a day, seven days a week.