OEM Toyota 2JZ Oil Pressure Sensor Adapter.
You will find on later 2JZ blocks that were in production for VVTI variants have the stock oil pressure location changed to a bigger thread pitch to suit a VVTI check Bolt. This adapter lets your use the factory OEM oil pressure sensor.
Note: This item doesn't come in the original packaging as I buy them in bulk. You can use a VVTI washer or a generic crush washer with this fitting.