Momentum’s unique filter-to-housing interface was built to feature the largest air filter possible. This 9” tall, pre-oiled 360-degree radial flow air filter features a 5-1/2” flange and our pre-oiled Pro 10R media with ten layers of progressively finer cotton gauze media for maximum performance and filtration. Its inverted top and large surface area provide much longer life between maintenance intervals, while reinforced metal provides maximum strength to prevent filter collapse.