The replacement parts accessory kits are smartly designed to be compatible with the Combo series Roomba. To maximize the performance of your vacuum cleaner, accessories, especially for pets, should be replaced every two months. The parts are durable and easy to install. Make your robot vacuum cleaner last longer. Compatible with 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 main brush bristles roll into this small box, it is normal. You can put them in warm water (about 85 degrees) for several minutes to get them back. It does not affect the quality and performance. Tip: Replace the spare parts every 2 ~ 3 months (depending on how often you use them). Color: green Material: plastic Size: about 177mm long Package contents: 2 * Main brush Only the above package content, other products are not included. Note: Light shooting 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.