Girard Perregaux have released a tourbillon version of their Opera One watch. The watch has a semi-transparent tinted sapphire dial giving the wearer a remarkable view of the movement. The Opera One features a Westminster chime which marks the hours using four hammers to play a combination of four different notes. The watch uses the manual Girard Perregaux caliber GP9899 movement with a power reserve of seventy hours. The case is made of eighteen karat gold with an alligator strap.