Air filter element for Vanguard powered 3000/4000 series tractors. Genuine Briggs & Stratton, p/n 394018 replaces Ingersoll C37544. See p/n 272490S for the matching foam pre-cleaner. Order p/n 805113 if you have the early design square pleated filter. Note, filters are shipped unboxed as we purchse them in bulk packs and pass the savings on to you!