This is a very light weight and light support sports bra. The material is very thin and silky … which is good and bad. For hot summer non-running adventures, it will be perfect; for dimming the headlights, not so much. I would recommend it for light impact activities like hiking or climbing or yoga. I would not wear it for running or dancing. The fit is a bit odd - the medium fits a 34 B/C well on the band but the actual bra part and straps are a bit looser than I would prefer. Overall it's fine, I'll keep it, but I would not buy it again.
I bought the medium, I have double checked this. I am 5 feet 8 inches and 121 pounds. This sports bra leaves indentations in my shoulders and getting in and out of it is an extreme sport. Fabric is great but it runs very small.