NEMA straight-blade receptacles mount to surfaces and connect with plugs to distribute power. Also known as NEMA outlets, they tap into existing electrical sources or provide access points on equipment to power them. They're made to standards designated by the US National Electrical Manufacturers Association, have different current ratings, and use various socket configurations to prevent mismatched connections. Commercial receptacles deliver connections in residential and business applications. Industrial receptacles have rugged constructions suitable for harsh settings where impacts, corrosion, and hot/cold temperatures are concerns. Hospital-grade receptacles are for healthcare environments and patient-bed locations. Watertight receptacles seal out liquids and debris to provide connections in wet and corrosive environments. Hazardous-location receptacles supply power in settings where ignitable gas, vapor, liquids, and fibers may exist.