Good replacement for original Dyson parts. Rear filter installation is fine, engine cartridge installation is so-so. It fits, but doesn't capture nearly as well as a Dyson filter. When deployed, it protrudes almost about 1/8 inch from the top of the motor, but it sucks in even when the unit is running. It seems to work fine, but not very accurate. I don't think you can complain about 1/10th the cost of Dyson filters. They work.