Profax MAK-400 – 400 Amp Miller Power Pin Kit The Profax MAK-400 is a heavy-duty 400-amp power pin kit designed for Miller® MIG welding machines. Built with precision and durability in mind, this kit ensures a secure electrical connection between your MIG gun and welding power source. The robust brass construction provides excellent conductivity, while the included O-rings and fittings create a tight, reliable seal that reduces wear and prevents gas leaks.