The watch collector César de Trey teamed up with Jacques-David LeCoultre during the winter of 1930-1931 to create a watch that could withstand shock, after witnessing a shattered watch during a polo match whilst travelling in India. The firm Jaeger S.A. was appointed by LeCoultre to create a reversible case using a unique slide and flip mechanism taken from the French designer René-Alfred Chauvot; this in turn was accompanied by a case back which could be personalised. This Grand Sport model uses an automatic calendar movement.