The Cusco Neodymium Magnet Drain Bolt is a cost effective investment that provides an extended safety measure to your engine. How? Magnetic drain bolts trap harmful metallic elements that float in your oil then later settle at the bottom of your oil pan when not driving. This will reduce both contamination and friction while all your internal parts are operating. Oil filters can only catch so much, and the metallic elements that don't get trapped will continue to circulate throughout your engine. Now you can take the extra step the next oil change, and use the Cusco Drain Bolt.