IWC, International Watch Co, Schaffhausen, Ingenieur, SL, "Jumbo", armbandsur 40 mm,

In 1976 the appearance of the Ingenieur changed conspicuously. Designer Gérald Genta gave the watch a completely new face and housed the large Ingenieur SL, Reference 1832, in an elegant, sporty steel case. This second major icon in the Ingenieur collection has remained one of IWC’s most outstanding and innovative designs to this day. The exterior of the Ingenieur SL, Reference 1832, measured 40 × 38 millimetres and was aimed both at technicians and an increasingly style-conscious group of watch lovers who also had exacting demands when it came to technology. The IWC-manufactured 8541 ES calibre, for instance, whose pallet lever, escape wheel and impulse roller were likewise made of antimagnetic material, featured a soft-iron inner case that was painstakingly mounted on tiny rubber pads, offering protection against magnetic fields up to 80,000 A/m and any kind of shock or impact. In itself, the watch was ingenious and perfectly in keeping with IWC’s image, but the time was not right. The company recorded a paltry 550 sales in steel. By now, this is water under the bridge and part of IWC’s colourful history. Today, the low production figures for the Ingenieur SL, Reference 1832, have made it a very much sought-after collector’s piece. And those who own an 1832 can count themselves extremely lucky.
Source IWC