Materials: Our metal nozzles are made of copper alloy. The nozzle prevents nicotine stains on the fingers partially reduces the inhalation of nicotine tar. Filtration principle: The pull rod filter is installed inside the nozzle. When cigarette smoke passes through the two holes of the connecting rod filter, it hits the wall of the connecting rod, causing condensation deposition of e-liquids. Implementation of pure physical function filtering Cleaning the filter: first empty the small be of the filter, slowly pull the lever to prevent the tar from splashing on the body, clean the filtered tar with a paper towel. You can poke a few small holes in the filter rod with a needle) Note: When you smoke 5-10 cigarettes, the filter usually needs to be cleaned once. As the inner wall of the tube is smooth, the new filter needs to suck 10-20 cigarettes to condense the e-liquid; If you don't use it f many days, you will find that the lever cannot be pulled. Initially, the filter can be immersed in hot water f 5-10 minutes.