The "Celtic Knot" pattern, a quintessential artistic motif of the 5th-century Celtic civilization, symbolizes a mysterious, unending design. It suggests that life has no beginning or end, and that the soul is immortal. The ingenious Richard Mille has fused this ancient, eternal symbol with an exquisitely complex tourbillon watch to create the "RM019," embodying a new concept of "timeless time."

On the skeletonized dial, a single line adorned with diamonds traces the Celtic Knot pattern, encompassing the barrel, power reserve indicator, and tourbillon. Within this flowing line, the off-center hour and minute hands elegantly mark the passage of time.

Turning to the caseback, the see-through sapphire crystal reveals a mainplate entirely crafted from black onyx. This rare natural stone is said to deflect harmful terrestrial energies and bring stability, long believed to foster a calm mind and enhance creativity. Further embellishing the onyx plate at the 6 o'clock position is a Celtic Knot design formed by three intersecting arcs, adding another layer of refined beauty.