3in.OD, 2in.ID, 1-7/16in.HK&N E-4188 is an oiled cotton gauze direct replacement air filter intended specifically for light industrial equipment. It's perfect for generators, air compressors, utility lawn and garden units, chain saws, etc. K&N high-flow air filters provide excellent filtration and engine protection while they reduce restriction to allow your engine to breath more efficiently. They're also washable and reusable. This air filter doesn't come pre-oiled, so it must be oiled before installation. A simple, step-by-step guide is included so you can be sure your filter is perfectly oiled. The E-4188 is designed to suit hundreds of applications.