These filters work great on Roomba 650. They snap and fit snugly. A small pad that sticks to the edges of the plastic case stays on it and doesn't come off. I did an hour cleaning with the first filter and it caught a lot of dirt (see attached picture). The filter itself catches a ton of dirt while still letting you breathe. I know this because I can feel the air coming out of the back of the Roomba. Given the low price/quantity and quality you can't go wrong. I'd be happy to pay a few more euros for these filters. I would happily repeat the purchase. A little remark. Once you have the official Roomba filters, they snap into the compartment very easily on the first try. With these new filters, I had to press each side (top corner) of the filter multiple times for it to snap into place. But after that everything is fine and they stay in place.