The Xiaomi Mi Vacuum Mop Essential Mainbrush Cover is the battery cover that houses the central brush for the Xiaomi Mi Robot Vacuum Mop. This cover protects the central brush and is required for usage. If your cover has broken or is not engaging properly then this main brush cover will solve the problem.The Xiaomi Mi Vacuum Mop Essential Mainbrush Cover protects the central brush on your Xiaomi Mi Robot Vacuum Mop Essential. It features a 304 stainless steel wire, sturdy cover that is easy to install with one-hand operation.