Heads up...this product is meant to be used exclusively on charging cables, not headphones.
Promising review: "I'm not sure what it is, but I'm hard on my chargers. I usually get two to three months before the plastic starts to split from the cable and I have to replace the whole thing. I've used Apple, Belkin, Anker, and Amazon Basics, which are great, but I still go through them. Then I came across these and tried them out. They're awesome! I've been using the same cable for six months now, which is the longest I've ever used one for. It's still going strong! These are a great little solution that cost a lot less than replacing lightning cords altogether."—Sophiehehe
Get it from Amazon for $4.78.