Hey Roomba owners! If you're tired of paying crazy prices for those official replacement bags, this 20-pack is about to save you some serious cash. These bags work with pretty much all the newer iRobot models - i7, i7+, i8, i8+, i3, i3+, i4, i4+, i6, i6+, j7, j7+, s9, s9+ - they all use the same Clean Base automatic dirt disposal system. The cool upgrade here is the self-locking sealing collar that uses latex to create this tight seal so no dust escapes back into your air when you're changing bags. They're made with two layers of melt-blown fiber filters plus two layers of non-woven fabric that captures like 99.7% of dust and even those tiny 0.3 micron particles. Each bag holds up to 30 bins of dirt, so you might only need to change it every few weeks depending on how much your Roomba works. Installation is stupid easy - just pop one into your Clean Base and you're good to go. At about half the price of the official bags, this 20-pack will keep you stocked for literally years. Each bag measures 4.1x5.7x6.4 inches, perfect fit for the disposal unit.