I am 17 Years old and when I look at my penis it does not look as matured as does I see in the locker room
My young friend. The picture looks like the average size 5 to 6 inch. We are all made different some are bigger and some are smaller. When did you start puberty. You can start from 9 to 14 and you can still grow till 21 Read up on it on the internet. It will help you out. Take care and relax Ken
Your phots shows a perfect mature man's erect penis. However, if you are comparing with other men, presumably they are flaccid in the locker room. - so shouldn't you be showing us a photo of yours when soft?
In the photo your penis looks really good healthy and good size, nothing to be concerned about.
Don't worry about size. Size depends on many factors including gene. It doesn't matter as long as you know how to use it. Hardness on the other hand depends on how excited you are and how good is your health. You have a long time ahead. Don't worry about size.