Review (4/5): Acceptable quality, great quantity!
There hair ties are surprisingly thin. It takes 2 or 3 of these hair elastics to be equivalent in thickness to an average hair tie, but that's alright given how many there are. That, and the fact that 40 of these costing about 6 dollars while other brands of normal thickness give you about 15 ties for the same price. Since I tend to lose hair ties like crazy, quantity is fairly important to me.
The biggest downside of these hair ties is how fragile they are. I tend to tie my ponytail pretty tightly, so the inner elastic breaks after 3 or 4 uses.
TLDR: Solid product that gives you tons of ties, but be careful about breakage.