NEMA locking-blade connectors attach to the ends of cables and have terminals that insert into plugs and inlets to distribute power. They secure when twisted to prevent unintended disconnections. These connectors are made to standards designated by the US National Electrical Manufacturers Association (NEMA). They are rated for different current ratings and have various socket configurations to prevent mismatched connections. Industrial connectors have rugged constructions suitable for harsh settings where impacts, corrosion, and hot/cold temperatures are concerns. Watertight connectors seal out water and debris to provide safe connections in wet and corrosive environments.