Shop Vac 903-04-00 or 90304 Cartridge Filter for Wet or Dry Pickup. Use for both wet and dry pick-up {Note: NOT for large quantity wet pickup such as standing water} and fits most Shop-Vac® wet/dry Vacs (7-3/16" Outside Diam - 5-5/8" I.D. x 6-5/8" Tall)(will not fit 1x1®, BullDog® Portable, Mighty Mini®, Hippo®, Hang Up Vacs or AllAround Series® with 1 1/2 or 2 gallon tank, 5 gallon contractor portable, heavy duty portable, floormaster plus, all around plus) Sug Retail 21.99