An automatic watch winds itself from the movement of your wrist. Wear it and it keeps running, with no battery and no charging.

Automatic in one paragraph

A small weight inside swings as you move. That winds a spring, and the spring releases its energy in even steps to move the hands.

The rotor and mainspring

The weight is called the rotor, and the spring is the mainspring, a coiled strip of metal that stores energy. A balance wheel sets the pace. It swings back and forth while a part called the escapement lets the energy out one small step at a time.

Power reserve

This is how long a fully wound watch runs once you take it off. The Noctra Obscura's Sellita SW200 movement has a minimum of 38 hours. Its balance swings four times a second, which is 28,800 beats an hour, and you can watch it through the opening at twelve.

Why it keeps ticking when worn

Everyday movement is enough: walking, typing, lifting a cup. That's why an automatic suits daily wear.

What happens if you stop wearing it

It runs down and stops. Nothing is damaged. To restart it, unscrew the crown, wind about thirty turns clockwise, set the time, then screw the crown down. Wind before you set.

Automatic versus manual wind

A manual watch has no rotor, so you wind it by hand every day or two. Some people enjoy that. An automatic suits anyone who wants a mechanical watch without the chore.