The official watch for the 1998 Swiss Alps Challenge is equipped with a Revue Thommen mechanical altimeter which measures the altitude from O to 4,500 m and, with its rotating bezel, the barometric pressure from 750 to 1,050 hPa. The titanium case, which has a screw-down back, is water-resistant to 30 m and houses an exclusive hand-wound 17-ruby movement with hours, minutes and small seconds. The winding crown is fitted with a special valve. Doublesided anti-reflective sapphire crystal. Limited series of 1,998 pieces.