The TiAL SS are rare, hard to get housings but we try to keep them on hand when possible. They are made of solid stainless steel & utilizes V-band inlet (manifold side) & outlet (downpipe side) The casted then machined stainless steel has a very smooth finish, both inside and out. Does not rust & is about 33% lighter then normal turbine housings. Very strong & withstands the heat with no problem. Mounts to Tial V-band flanges using Tial V-band clamps & doesn't need or use studs/bolts or gaskets. They have a smaller physical overall size but flow like a larger housing. On average, there are 3 A/R options for each turbo.