This shallow depth 0.5" mild steel weld fitting (bung) & plug kit for Innovate Motorsports wideband O2 sensors is an alternative to the 1" mild steel version included as standard with Innovate Motorsports products. Choose this option for installations that require increased sensor heat and exposure to exhaust gasses or that could benefit from a bit of extra clearance between the sensor and nearby components such as floorboards or drivetrain components.