Mann Filter metal-free oil filters are developed using the EvotopĀ® filter element that is a further development of high-performance oil filters and is environmentally friendly that can be incinerated without leaving any residue. Mann Metal-Free oil filters are designed specifically for modern engines to deliver superb results on intensive use. Additional features like a non-returning membrane retain the engine oil in the oil module as soon as the engine stops. The membrane offers a faster and more optimized oil supply when starting the engine compared to a conventional return stop valve installed in the housing.