The DRIPLOC Oil Only Sphag Pillow Standard Filter is used with the Driploc 4" and 7" Rack Systems. Non-leaching oil absorbent is perfect for catching and containing spills.  The replacement filter is packaged in a plastic sack.  It is recommended that you place the old filter in the plastic sack to make the replacement as clean and easy as possible.  Pillows measure 17" x 23". Grease filters are normally changed after each exhaust fan cleaning, however, grease exhaust volume will dictate changing frequency.