True greatness comes from within, but is often clearly visible from the outside. The Big Ingenieur, for instance, has an impressive 45.5-millimetre case that is necessary because the extra-large 51113 calibre with its Pellaton automatic winding and 7-day power reserve requires more space. Not everyone, of course, works in high-energy environments, surrounded by strong magnetic fields, so the designers did away with the soft-iron inner case in favour of a sapphire-glass back. This modification provides an unimpeded view of the fascinating movement, significantly reduces the height of the case and makes the watch more comfortable to wear. The watch is available in platinum and rose gold with a silver-plated dial or in stainless steel with a dial in black. Another by now unmistakable IWC feature – the last day indicated in red on the power reserve display – adds a striking touch.