This is a wide band lambda sensor, to fit auto tune modules and dynos. Comes with 5-wire, broadband, flat contacts in connector, 18mm, 23" OAL wiring harness. Wideband air-fuel ratio sensors perform the same function as the regular (lower cost) O2 sensor, but they are able to work over a much wider air/fuel ratio range, more precisely measuring the amount oxygen in the exhaust. Narrow band sensors just switch between rich (too much fuel, not enough oxygen) and lean (too much oxygen, not enough fuel). Wideband sensors use a more costly sophisticated sensing element that provides a signal to the vehicles ECU for a much better air fuel ratio over a wider range. - Advanced Wideband sensing element for exact air/fuel measurement - Robust sensor design increases sensor longevity - Seared protection tube due to 100% functional quality test - True direct-fit OE connectors and harness - Pre-coated threads with anti-seize compound right out of the box