it is General Purpose vac replacement cartridge vacuum filter; It fits for craftsman wall vacs with stock number 9-17775; WALL VAC made from 2002-2004;How to Assembly this NEW Replacement Filter? SEE THE STEPS BELOW:1)Unscrew and remove filter cap and slide dirty filter off of filter cage;2)Dispose of filter in waste container; 3)Clean vac lid thoroughly;4)Install new filter and filter cap;5)Tighten filter cap;