The replacement parts are cleverly designed to be compatible with the Roomba Combo series. 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 accessories for the Roomba Combo series. 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 °C) for a few minutes to get them back. It does not affect the quality and performance. Tip: Replace spare parts every 2-3 months (depending on how often you use it). Color: green Material: plastic Size: about 177 mm 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 to differ slightly from the real thing. The allowed measurement error is +/- 1-3 cm.