The quality of these bags are pretty good - Thick and sturdy so things rarely poke holes, the drawstring ties are helpful. But because they are made to fit to the trashcan size exactly and there is no "give" to the bags, I find they are very difficult to make fit in the trashcan. 

The proper use is probably to fold the top of the bag over the top of the trashcan and under the metal frame the plastic bin sits in. However, I prefer to touch my trash the least amount possible, so if you only fold the bag over the top of the plastic bin, they are constantly popping off. I'll be buying a larger size next time.