Cling it on the clean walls or any other flat indoor surface and make sure to squeeze out the air backside. When cling for a long time without remove.It will adsorb the dust in the air.So keeping the air clean helps to reduce dust on sheets and the wall surface around. The cling power will be weaken after stick and reuse for many times,under this condtion,please make sure to totally squeeze the air backside out. The sheets can be reused for more than 10 times in the normal indoor humidity and temperature. Don’t use under the following conditions:extremely in high humidity,strong wind environment,place full of dust surfaces of textile ,environment with fire.