The Guardian long & short sleeve shirts feature a semicompression underlayer from the lower chest to the waist, constructed with VaporCore™, powered by 37.5® Technology, designed to comfortably conceal and allow fluid access to firearms without chafing the skin.
I ended up getting every configuration of this shirt, all 7 of them, Polo and Button Up. At 6'2 and 220lbs of a fit build, these shirts fit well and do what they are advertised to do at an XL size with a Glock 19. Amazingly, the sewn in barrier to gun/knife/weapon, whatever is you wear at the waist works so well, that I can't believe its taken so long for somebody to figure this out. I'm pleased. Verx, come out with some more colors.