IP03 3/8″ NPT Industrial GoldPlug Magnetic Drain Plug Internal Head

3/8″ Industrial National Pipe Thread Magnetic Drain Plug. Pulls metal particles from your engine.

3/8″ NPT actually measures 0.67″ in diameter.

5/16″ Internal Hex

3/8-18 NPT Threads,  0.313″ Internal Hex, 0.415 OAL