Well, as we do not wish to advertise any company in particular, we would like to advise you to go for one of the biggest penis extender companies. You will have no problems finding out which these are as they already have a reputation and they are bonafide companies registered and licensed to make medical devices. If you start thinking that you could save money on a cheaper knockoff, remember that you will be putting that device on your penis. You do not wish to have subpar quality in a device that is going around your penis, would you?
You can always check out different websites that are aimed at people who are looking for their penis extender. For instance, you will find plenty of penis extender review websites where you can find all the different information on the different extenders available today. You can see all the specifications, perks of different solutions as well as prices and everything else that might be important for you in buying your penis extender.
You can also check out some public forums and other places online where people get together to talk about the penis extenders they have had experience with. Here, you can find the most objective information and you can be sure that no one is being paid to praise a certain product while slamming the next one.
If you wish to do all the research on your own, then you should first look into the company that is manufacturing the penis extender, about where they produce their devices, about whether they have all the necessary certificates that they are allowed to produce them. Only when you have ensured that you are dealing with a serious company can you start looking into different characteristics of the very device.