The legendary Corum Bubble is all about its case and crystal, a sensuously formed case with a gigantic sapphire crystal that rises relentless upwards. Now Corum has infused the traditional arts of high horology into the Bubble for the very first time, with a pair of Bubble tourbillons in rose gold.

Perhaps the most complicated Bubble ever, the Bubble Tourbillon Chronograph combines two of horology’s most revered complications: the tourbillon and the chronograph. And making it even more singular is the fact that the Bubble Tourbillon Chronograph is self-winding, powered by the CO398 movement exclusive to Corum.

Shaped like the Corum key logo, the tourbillon cage is visible at 10 o’clock, giving life to the dial as it makes one revolution a minute. Operated with two pushers on the case, the chronograph records the seconds on the central axis, while the minutes are counted on the register at six o’clock. As is essential for a true haute horlogerie timepiece, the chronograph is controlled with a column wheel that functions as an on- off switch. This is both more refined and complex than the cam found in industrially produced chronographs.

Equipped with the similarly exclusive, automatic CO397, the Bubble Tourbillon GMT features a tourbillon regulator and a second time zone display. Displayed on a rotating disc at six o’clock, the second time zone can be swiftly advanced in hourly intervals via the pusher at four o’clock. The second time zone is read in tandem with the day and night indicator at eight o’clock.

To emphasize the optical effects of the massive Bubble sapphire crystal, both tourbillons are fitted with pale grey dials decorated with a concentric guilloche that accentuates the contours of the dial. And as befits high complications, the Bubble Tourbillon GMT and Tourbillon Chronograph feature hand-finished movements decorated with traditional techniques like chamfering and straight graining. They share the same, iconic Bubble watchcase, hewn from a block of 18k rose gold and polished to a mirror finish.

Each is limited to just five pieces.