Girard-Perregaux calls the timepiece the Quasar Azure. What’s special about it isn’t only its case, which is fabricated from a single chunk of sapphire crystal—and helps give the watch its name.

This watch also features an update of a component which Girard-Perregaux calls their ‘Neo-Tourbillon with Three Bridges’; the mechanical marvel is designed as a modern revision of a tourbillon that the company produced well over a hundred years ago. And, with a fully transparent polished case, the watch’s tourbillon is on full display.

Also featuring the GP09400-1035 caliber, the Quasar Azure boasts a 60-hour power reserve. Materials include titanium, white gold, and an anthracite strap. It is priced at ~$300K.