Magnetic plugs are a small investment that can help to prevent damage and wear in engines and gearboxes. Use them to replace standard oil gallery plugs and drain plugs in oil tanks, cooling systems and transmissions. They provide an easy way to check for unusual wear which may precede a failure. These plugs require a sealing washer such as our Stat-O-Seals, Part No. 3245-7/8 (sold separately).