The C1 QuantumGravity is a mechanical watch. That is the heart of its appeal. Most inexpensive watches have been digital since the 1970s; using the properties of quartz crystals, electronic watches can be mass produced at low cost, yet keep very accurate time. Mechanical watches have become specialty items, sought after for the same reasons hand-crafted musical instruments or hand-painted figurines are. To understand what's so special about the QuantumGravity, we need to know a few things about how mechanical watches work.
Mechanical watches are powered by a spring (called the mainspring) that gradually unwinds, releasing the stored energy to move the gears of the watch. The mainspring can be wound manually or automatically, via a weight that turns a winding mechanism as the wearer moves his or her arm. As the mainspring unwinds, it moves the gears which in turn move the hands of the watch.
The key component of a mechanical watch is called the escapement. The escapement is what converts the unwinding of the mainspring into steady, precise movements that translate to accurate timekeeping on the face of the watch. There are many different types of mechanical escapement, but they essentially cause a gear to turn a specified amount, then "lock" against a pivoting mechanism of some kind. Then the pivot moves and the gear turns a small amount again, until it locks again. This is the process that actually causes the ticking sound of a mechanical clock.
Gravity can affect the accuracy of an escapement, which means that if you hold a watch in one position, or leave it sitting on a nightstand, it won't be as accurate. This led to the development of a mechanism called a tourbillon. A tourbillon is like a cage that the escapement rests in. The cage rotates, typically once every minute, as part of the watch's movement. This prevents gravity from acting on the escapement in only one direction even when the watch is in one place.
Another mechanism that can be added to mechanical watches is one that keeps track of the power reserve. The mainspring in a wound watch can store enough energy to run the watch for 24 hours up to a week, depending on the model of watch. A power reserve indicator measures the tension left on the mainspring and translates it into the movement of a dial that shows the wearer how long the watch will work before it needs to be rewound.
Now that we understand some of the basic mechanisms in a mechanical watch, we can figure out what makes the QuantumGravity so special.