You probably have seen such cover at many motorcycles or cars. And you might be asking yourself a question, why you might need it? So the simple answer is that it absorbs the liquid which sank from brake or clutch reservoir and makes sure you are safe while driving a car or riding a motorcycle.
As an example, there is one produced by Mugen which fits both Honda cars and motorcycles, but almost any car manufacturer has such a product to offer. You can find products for Nissan, Subaru, and Toyota in our catalogue.