These 14" disposable wall washing mops are to be used in areas that are considered to be cleanrooms rated class 100 or higher. These rooms are most commonly found in a manufacturing plant, or in a scientific experimentation research facility. Cleanrooms are 10,000 times cleaner than a hospital operating room. It takes an incredible amount of technology to achieve and maintain such cleanliness. Huge air filtration systems completely change the air in cleanrooms about 10 times per minute, reducing the chance that there are airborne particles that might harm the chips. These mops are made from a lint-free polynit polyester material to insure that no particles will be left in the air.