So how come these parts fit my Roomba 650 better than the set of 'authentic' parts sold by iRobot on Revain (really?). They fit perfectly and work great. You really saved my day. If I had just ordered a set of "authentic" parts I would still be waiting to use my Roomba because they don't fit at all where these fit perfectly. I just used them on my Roomba to vacuum my whole house and I can assure you they did a very thorough and excellent job! I would not hesitate to order them again.