AISEN (Pack of 2 Air Filter + Pre Filter for Briggs & Stratton 3.5 to 6 HP Quantum Engine Lawn Mower 491588 399959 271933 491435 Pre filter replace 271933 491435 491435S 493537 493537S Air Filter replace 491588 491588S 399959 For Briggs & Stratton 112200 12A800-12T899, 128700-129799 and 92200 series 3 to 5 HP horizontal, 3.5 to 6 HP Quantum and 6 HP vertical small engines