I bought these for my Roomba 655 after buying genuine Roomba parts at a much higher price. I compared them side by side and the only differences I noticed were very minimal. The main thing I noticed is that the Roomba hubs/casters spin a little better if you hold them by the yellow part and spin them, but it's so insignificant that I can't imagine it worth the extra cost are worth. Everything else seemed identical. I'm currently using these parts in my Roomba and it's still doing a great job of keeping my floors clean. I would highly recommend them if you are hesitant to buy aftermarket parts and want to save money.