SERIOUSLY COOL WORKWEAR THE DESIGN To help you keep your cool, air vents have been strategically designed and located at all key sweat points – under the arms, across the shoulders in the front of the shirt, across and down the back. These vents allow the maximum amount of air to flow around your body to help you stay cool and dry. The above shirt features 16 vents (E1370ST). We also have an 8 vent (E1371ST) style that eliminates the back vertical vents. So choose the shirt that best suits your needs SUN SHIELD STRETCH RIPSTOP FABRIC ULTRAVIOLET PROTECTION VENTILATION