This is a men's blue and black jersey-style motocross shirt made by MSR. The shirt does not have a size tag and measures about a size large.
It measures about 22" underarm to underarm, 30.5" top of the shoulder to the sleeve opening, and 31" from the back of the neck to the bottom hem when laid flat.
The jersey is in pre-owned condition with some snags and wear throughout the shirt.