This is a vest to be worn over your workout clothes during your YOSA or Rururon time to help you sweat even more. There's a significant difference in how much you sweat when wearing just your clothes versus wearing this vest. You can also wear it during winter when it's cold. This is for anyone looking for a good deal. I had a few of these vests, so this one hasn't been worn many times and is in excellent condition with no tears or stains. Thank you for looking.