[Good Sealing] The dust bag is made of melt-blown fabric and non-woven fabric, combined with cleaning station can effectively capture 99.7% of ultra-fine dust down to 0.3 tiny particles. [Auto Lock] It lock automatically when you lift dust bag, completely sealing dust bag inlet to dust and dirt stay inside bag. [Tips for Use] In order to keep your robot running at its , please clean and replace parts in time. If you have allergies and pets , it is recommended to replace dust bag every 2-3 weeks. Large capacity: The dust bag has a large holding space, which can collect more dust and reduce cleaning frequency. Easy to replace: dust bag design is simple and easy to use, easy to replace, no special tools or professional skills are required. Quantity:A:4PCS Color:As Shown Material:Non-woven fabric Package Contents: 4 * Dust Bag Only above package content, other products are not included. Note: Light reflection and different displays may cause color of item in picture a little different from real thing. The measurement allowed error is +/- 1-3cm.