Waste can be unloaded directly into the "open top" of the trailer, but is most often unloaded on the tipping floor to allow for materials recovery and waste inspection before being pushed into the trailer. Large trailer, usually 100 cubic yards or more, are necessary to get a good payload because the waste is not compacted. This is a simple technology that does not rely on sophisticated equipment (e.g., compactor or baler). Its flexibility makes is the preferred option for low-volume operations.