They do work. Better for some people than for others. The maximum tension they present is only in the 2.2 pound range, so they're meant to be worn for long periods of time, or at least for shorter segments of time (and then taken off for a while) which across all sessions equals a lot of time. If you find a 'gain-calculator' on any of those sites, the figures given are typically for 12 hours per day.
I used a similar device early on for around 3 hours / day in a single session, along with sporadic jelquing - usually with a jar lifter. (two or three times per week, and some weeks none at all). Gains were the quickest during that first ~14 months. It might well be that everyone gains the easiest at first?
(I was only aiming for 1.5 inches all total and currently have gone 1.75 ... but it could have been accomplished in way less time. Don't be sporadic.)
In that program, if it could be called that, the [words=https://shop.mattersofsize.com/products/sizegenetics-penis-extender]traction[/words] device -- even at only 2.2 lbs -- keeps protracted tension on your rod during remodeling from the jelquing sessions. Seems to work pretty well as an -addition- to other Penis Enlargement methods. The [words=http://www.mattersofsize.com/forum/penis-enlargement-newbie-forum/1597-dlds-first-routine-i-gained-2-inches-with-this-routine-full-tutorial.html]Newbie Routine[/words] is a good place to start as a routine.
As for the AndroMedical device, there are better ones available, notably everything by a maker that hangs out (no pun intended) around this board. Link to a thread about it --
http://www.mattersofsize.com/forum/showthread.php?t=26955
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