This is what it is - an extension cord for my headphones. What I never liked about coiled cords is the tightness and constant tugging against the headphones. While it may say 20' extension, don't expect to be able to use much more than 10' of it without the cord yanking the headphones, or in my case, earbuds, from your head. I'm always having to stretch the cord out and then finding a seat cushion or something to anchor it with so that it doesn't pull the earbuds from my ears. This is the only way to use a coiled cord and still have some freedom to squirm around in your seat or toss and turn in bed.
I'll recommend them because there aren't many other options out there when you walk into a store to grab something like this off the shelf. I also understand the purpose of the coiled cord to act like a shock absorber, which is great when you walk around and listen on your headphones, but for sitting down to listen, you're better off finding a straight, uncoiled cord.