This oxygen spacer spaces out the secondary (rear) O2 sensor to remove MIL or CEL issues caused by removing the factory catalytic converter. Professionally manufactured from stainless steel. Works with most O2 sensor designs on the market. Spacer will add approximately 1.7" to the height of the sensor. Features a flare seal seat, so no sealing washer or gasket is required. Install with anti-seize. For off-road use only.