The only USAF-approved shirt for wearing under (or over) your uniform, whether that be coveralls, ABUs, AFPTU, or service dress.
Front - CMSAF #18 Kaleth O. Wright & an MP5
Back - Enlisted Jesus Is My Homeboy
Pre-shrunk 100% cotton
Double-needle stitched neckline, bottom hem and sleeves
Seven-eighths inch seamless collar