The replacement parts accessory kits are cleverly designed to be compatible with the Combo series Roomba. In order to maximize the performance of your vacuum cleaner, accessories, especially for pets, should be changed every two months. The parts are durable and easy to install. Compatible with For Roomba Combo Series robot accessories. Compatible model: For Combo 113 R113840 (Please confirm your vacuum cleaner model before purchasing). Note: If the side brush or the main brush bristles roll into this little box, it is normal, you can put them in hot water (about 85 ) for several minutes to get them back, it will not affect the quality and performance. Tips: Replace the spare parts every 2 ~ 3 months (depending on your frequency of use). Colour: greenMaterial: plasticsSize: about 177mm in lengthPackage Contents: 2 * Main brushes