Guys look at pumps, pill, potions, lotions, and anything else they can get their hands on, but these are not the best choice if you are dead serious about getting permanently larger.
The best thing to do is hand routines.
This article explains how hand routines compare to using stretching contraptions, and other oddities.
Anything that uses steel or weight aren't a smart idea for most men due to some key reasons.
For starters  these contraptions are not in huge scale production and so a lot of guys build their own stuff.
These self built devices are very dangerous, because of the extreme amount of weight used in them.
Usually an anchor wrap is placed around the manhood with a piece of rope or string hanging off of a dumbbell or weight plate.
  Right near the point of attachment there's rather a ton of pressure built up here and it can get very dangerous/ A lot of times the anchor wrap slips guys get cut or bruised or get a  severely damaged penis.
Most of the men who build these things are people who have done hand workouts and want to accelerate gains or go for 3.
5 to 4 inches of gains.
Some of these men are a bit crazy, and have a few screws loose.
It is a much better idea than just using your hands, because you very simply eliminate the need to have another item of cost and you don't risk injury.
Simply using your palm and fingers can get you 1-4 inches larger, and the results last for life once you get them.