Abstract: An improved magnetic filter adapter for use with removable fluid system filters. The magnetic filter adapter of the present invention includes an adaptive filter housing removably mountable to a fluid system filter, magnet means for attracting metallic particles from the fluid flow within the filter toward the interior surface of the filter external wall, and an inner magnetic-field concentrating cup for concentrating the magnetic force of said magnet means such that the potential field strength of the magnet means is optimized.