This little plate is designed to sit between your factory recirculation valve (aka bov) and block airflow, giving you a nice little bit of dose when you close the throttle. You will need to use a sealant of some kind to prevent air leaks, I would suggest RTV/FIPG silicone, or aviation sealant. You could also use two factory gaskets but those are expensive.

This will not work if you print it from PLA or other temperature sensitive materials, it will quickly go soft and deform, leaving you with a gigantic air leak, or potentially an intake system full of melted bits of plastic. Please print this from ASA, ABS, PETG, Nylon, or other high heat capable plastics unless you want that to happen. I would also suggest printing with a wall thickness of at least 1.5mm and 50% infill to give the part some strength, as you will be clamping it between two cast aluminium objects with some decent force.