Here's what other sites are saying:
The Brooks HVAC Synergy T-shirt is built to keep you cool during workouts in warm weather. Lightweight polyester fabric is soft against the skin, dries quickly and wicks moisture away from your skin. Mesh fabric under arms, along sides and on back increases ventilation. Side panels contain silver fibers that help fight odors. Fabric protects skin from UV rays with a UPF rating of 40. Flatlock seams ensure chafe-free comfort that'll keep you going for miles. Reflective details increase visibility from any viewing angle. The semifitted Brooks HVAC Synergy T-shirt is not too tight and not too loose.