Fully breathable dry fit material with a reflective logo on the left lower back area.
Please refer to the size chart in the photos section, as well as the instructions below on how to use it:
Measure (in inches) from one inch below the armpit, across (not around) the chest, to the same area on the other armpit. This will give you the width. Then use this to find the corresponding size on the chart. Or you can get a shirt that fits you well, lay it flat, then measure the same way as above.