General description Replacement Parts Dust Bag compatible with IRobot Roomba I3, I7, I7+, S9, and E5 Robot Vacuum Cleaners. Made from high-strength, environmentally friendly materials, these dust bags are designed for easy installation and optimal performance. It is recommended to replace the dust bag every 1-2 months for best results. Technical specifications Material: Cloth Package Contents: 6 x Dust Bags Measurement allowed error: +/- 1-3 cm