They have a penis extender that adds inches its takes a few moths however you ever want to know anything about then just ask
I think you've likely reached the limit on that one...I suggest whatever size you are, know that the average size is 5.5" and many if not most women are most comfortable with that size...if you are smaller than average, learn how to use it to please your lover or other techniques to do the same..most women that I have known aren't too crazy about having a baseball bat sized penis hitting their cervix and other organs...
Discuss with your lover(s) what pleases them, and let them show you and LISTEN..plenty of foreplay, etc
Jim