With the GST Perpetual Calendar, IWC merged the mechanical complexity of the caliber 79261 movement with the sturdy and sporty looks of the GST line. It was available in either titanium or stainless steel, and with the dial markings done in either German, English, Italian or French. Please note that the dial language is not always reflected in the provided pictures.Reference IW3756-06 has a Stainless Steel case and a Grey (rhodium-plated) dial.