As a product expert, make sure to choose only genuine LEVOIT accessory that will not only protect your humidifier, but will also justify your investment. Each packaged box contains 10 absorption pads for your convenience. These pads are specifically designed for Levoit LV600S, OasisMist450S, OasisMist600S, and LV600HH humidifiers to enhance their performance and prevent mineral buildup on the heating plate. The specially manufactured nylon pads are highly absorbent and durable. On average, the descaling pads will last 2-4 weeks, depending on the water hardness.