An Excursion Funnel is a testing element in Portal 2. It has two functions, which can be usually changed with a switch or button. These two functions are: a tractor beam-like function that pulls you towards the emitter, and a repulsor function that pushes you away from it. The device generates a beam that floats you and moves you, as well as gel and objects. In Portal 3, there is a third function, which is white, and simply makes objects hover in place to buy time or to just annoy you. The various functions do not affect energies such as high energy pellets.