I try my best to sit as far away from TV's as much as possible these days, because I know for a fact that it does damage your vision. And if you're sitting in front of video games for many hours way too close without breaks, then you are guaranteeing yourself a brand new pair of glasses in the distant, quite possibly, near future. This is the reason why I always purchase extension cords for gaming systems that do not carry wireless control pads.
I recently bought the Retron 3 clone system, which allows you to play a majority of NES, SNES, and Sega Genesis games. Since the system allows the player to use the original controllers for those three systems. I assumed the extension cables would also work with the system, and they work great.
The Sega Genesis Control Pad Extension Cord is listed to add an extra 6.5 feet to the controller and I think it does, which is great because in addition with the controller cord length, it gives me about a good 13 foot distance from my 52 inch TV. Plus it gives the player enhanced movement and flexibility. The extension is very easy to figure out and use. The connectors fit on the controller and into the system, with the larger head connecting to the controller giving it a nice firm connection. Therefore, disconnections aren't easy at all. The packaging comes with a small instruction booklet but I don't think it's needed.
In closing, if you still have a Genesis, or plan on buying a Retron 3, I think this will be a great investment. It's a shame that only one comes in the package, and last I checked they were pretty expensive. But I'm sure there are some cheaper ones out there.