This is a Bosch LSU 4.9 industry-standard heated 5-wire EGO sensor. These wideband air fuel ratio sensors are the very latest from Bosch and are used in many top quality tuning devices and also by professional dyno-tuners. Suitabe replacement sensor for the Prosport USA wideband kits.

Downpipe RAGE - Subaru WRX 1994-2000 3"
Delta fin Intercooler - 300x160x65
Denso Kinugawa 600cc injector set (4) GDA GDB 