The Pure Screen is a welded stainless steel screen that slips onto your racking cane or keg dip tube and filters out fruit or dry hops from the fermented or whole hops and trub from the kettle.  Also allows hopping to be done directly in the keg.  Stainless steel construction makes it easy to sanitize (do not use bleach!)  Not recommended for use with plastic racking tubes or plastic fermenters- it can cause scratching and possibly infection.  Pellet hops have a tendency to clog the Pure Screen-- it works far better with whole hops.