With additional packing rings, both between plug housing and contact inset, and between contacts and contact inset, the Series M1 Plus plug connectors are longitudinally watertight to IP67, even when unplugged.

The M Series plug connectors are universal industrial-quality connectors. They offer maximum reliability and safety even in rugged environments. Vibration, dust and aggressive liquids or vapours are often the cause of malfunctions, and can lead to safety problems. The M Series by Schaltbau offers a solution: the plug connectors are dustproof and waterproof, with protection class IP67. They are also to a high degree insensitive to acids and lye, and to heat and cold. In addition, the M1 Plus plug connector is longitudinally watertight to IP67, even when unplugged. The series is particularly useful when reliability in difficult conditions plays an important part, such as in environmental technology, traffic systems, the food industry, and mechanical engineering.