The AEM Inline Wideband Controller & Sensor provides a wideband signal to engine management systems to measure air / fuel ratio.
This external wideband sensor kit is commonly used with engine management systems (like the AEM Infinity 506) which include one internal sensor, but need an additional external sensor for supercharged, twin-turbocharged, or naturally aspirated applications.
If being used with the NSX, consider the ScienceofSpeed Single External Wideband Sensor Power Kit to power this sensor, or the Wideband, Fuel Pump, and Accessory Power Kit for more complex power needs.