It’s a billet aluminum intake manifold adapter (or inlet elbow/adapter) for a Toyota 1HD-T (1HDT) 12-valve turbo diesel engine (common in 80-series Land Cruisers). Plazmaman has designed this CNC billet aluminium inlet adapter for the Toyota 1HZ / 1HDT 12 valve engine, to simplify aftermarket intercooler installations by converting the factory 4 bolt flange, to a simple 2.5" (63mm) O.D push on hose barb. I bought this to install a custom intercooler but I ended up buying a full kit that included another one. This is a very high quality piece