Heidelberg FI-40 (2005) is an industrial false unit / flat-staple trailer (flat arrows feeder/folding unit) from German Heidellberg. The unit is used either as a stand-alone false station or as an additional unit/module in an existing Heidelberg Stahlfolder line to extend the capacity with additional rifle, fake or perforation sections on A3/A4 formats. The FI-40 series (where "40" indicates an inlet width of 40 cm) is characterised by Heidelberg's well-known building quality, precise rolling pressure and simple fine-tuning for even sheet feeding without double drawing.