Usage Tips:[Perfect fit for S9]:This IRobot roomba s9 rubber roller is perfectly adapted to the IRobot Roomba s series s9 (9150) s9+ s9 Plus (9550) IRobot vacuum roomba and can be purchased with confidence after determining the model of roomba you hold. [High Quality Main Brush]:The two main roller brushes of the IRobot roomba are made of rubber, which is environmentally friendly and non-toxic, and can be reused after a simple cleaning. We recommend replacing the rubber brushes once every two months to ensure that the IRobot roomba works perfectly. Colour:green Material:plastic Size:25 x 2.8cm Package Contents: 8 x roller brush Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.