This is a Vertx Short Sleeve Shirt known as the Coldblack, model F1 VTX4000P NV MEDIUM.
The Vertx coldblack(R) polo allows users to stay cool. Exclusive coldblack(R) technology combined with moisture-wicking fabric reflects 80% of the sun's UV rays and lessens heat absorption - resulting in a light" breathable shirt ideal for warm weather missions. Streamlined design" convenient sleeve pockets for pens and pencils" and a no-roll collar give this shirt a professional look with all the tactical functionality to get the job done.
Features:
Durable mesh fabric provides high-performance breathability
Superior moisture transport wicks sweat away so you stay cool and comfortable
No-roll collar