This high-quality refill is made of 100% microfiber for streak-free cleaning;The EasyWring Spin Mop refill has soft, absorbent strings that will not scratch floor surfaces;This mop refill is ideal for use in mopping all hard-surfaced floors;The O-Cedar EasyWring Spin Mop refill is machine washable up to 10x;Convenient bulk package of 4 refills