The Microfiber side is perfect for dry dusting or quick mopping on many different surfaces and the scrubbing side is great for tough stains or sticky messes. The large, flat sponge head covers a large surface with every swipe. Sponge heads are securely attached with Velcro and are interchangeable and replaceable. Refill for the OXO Good Grips Double Sided Roller Mop item #1339580.