This is a size M. I purchased it online from the Nike store. The original price was around 8,000 to 9,000 yen at the time. I wore it once and then stored it in the closet. It's in good condition, but please refrain from purchasing if you are concerned about minor details (there are no stains). I think it's easy to match and can be worn for everyday wear, running, the gym, or warming up before a race. You can store small items in the back pocket. Please confirm the size to ensure it's correct before purchasing. Thank you.