A static device with no moving parts used in a pipeline carrying fluids that causes the fluid streamlines to cross one another thereby intimately mixing the fluid. It is used to mix fluids such as dispersing gases in liquids, assist with dissolving solids in liquids, and mixing immiscible liquids. It consists of a twisted ribbon of chemically inert and unreactive material such as metal or plastic of sufficient length to provide good mixing characteristics. It is held firmly in place. It is also known as a static mixer.