When I first heard about this product I thought that it was a very weird idea and that it would never keep my hair in a ponytail or in my very loved messy bun.
I really ate my words because these are great, they keep my hair in a bun, a top knot and a pony with ease without giving me a tension headache or pulling my hair out, it's also great because it doesn't leave you with the kink that normal hair ties do.
The price is incredibly high for these but I was able to find a cheaper option in a Chinese store, I've gotten several friends including my office of twenty girls loving this product.
The only problem I find is that it doesn't keep my hair firmly together when I braid it, that is simply because my hair is thin pen rat the end of its braid then the invisibobble is.