MAGNETIC ENGINE OIL PAN DRAIN BOLT PLUG NUT CRUSH WASHER, M16x1.5 BLACK COLOR Suitable for Honda Toyota Ford Mazda magnetic drain plug is to help keep harmful metal shaving out of your engine. Over time your engine components wear down they will start to release metal shavings into your engine oil. These plugs have an incredibly strong magnet to help gather this debris directly out of your oil during operation. When it comes time to change your oil just clean off the magnetic end and re used it.