i have been using two different penis extenders. One is from x4Labs, and the other from Phalosan.
The x4Labs is alright and helped to correct my bending Peyronies decease a bit, after 6 months of usage around 5 hours per day. It is usually uncomfortable to wear... and it extended the length of my penis in the flaccid state by 0.5 inches permanent, but nothing at the erect length. Again after 6 months of use.
Now Phalosan was much better. At six months of use, this more expensive extender is very comfortable to use all day long; it has slightly improved my girth and length while erect penis. The length about 0.5inches in 6 month of using this extender 6-7 hours per day! I could wear this extender all day though as it is comfortable. So, in my opinion, this Phalosan device might achieve me up to one inch length and a bit more girth (as it is also a vacuum device 2-in-1). I can't see it giving me more than an inch though.