The Edelbrock #91171 Wide-Band Oxygen Sensor is a replacement Sensor for use with Edelbrock #91170 2-Channel Wide Band Air Fuel Ratio Monitor and Edelbrock #3532 Wide Band Air Fuel Ratio Monitor. Includes a Bosch LSU 4.2 Sensor with square connector for Edelbrock 2 and 8 channel Wide Band Air Fuel Ratio Monitors.