This humidifier filter is made of 100% natural cotton and designed to do the optical media water treatment and deodorization. It is made of microfiber water absorption material, absorbs water quickly and evenly. It is safe for children and pets; The filter effectively removes bacteria and other particles from the air that affect your respiratory system. The cotton swabs allow your humidifier to work more efficient. It would be better to change them regularly so as to ensure accurate operation of your humidifiers. The pad can be cut at any length suitable for your humidifier.