Rolex Definitions

Aperture
A tiny opening on the dial that displays specific information such as the day of the week, date, month, or moon-phase. Also called the “window” and may also feature a magnifying lens (known as Cyclops lens on Rolex watches) for easy viewing 

Bezel
A ring that surrounds the crystal on the top side of the watch and keeps it in place

Case
The container that houses and protects the internal watch movement

Case Back
The cover on the rear side of the case that seals off the internal mechanical components of the watch. 

Clasp
The component that fastens the watch to the wrist

Crown
A button outside the case on the right side that is used to set the time and calendar. It is also used to wind the mainspring on mechanical watches.

Crystal
The transparent cover on the top side of the watch that shields the dial and reduces glare.

Dial
A metal-based plate seen through the crystal that displays time in the various intervals available in a particular model, including hours, minutes, and possibly seconds.

End link*
A short link segment that is attached on the top and bottom sides of the case in between the lugs

Hand
An indicator that travels around the dial to point at the current hour, minute, or second of the day. Watches generally have hour, minute, and second hands. Analog watches also feature a center hand that indicates the date by pointing to date markings outside of the dial on the bezel*.

Jewel
Tiny sapphires or rubies on the movement that serve as gear bearings in mechanical watches to reduce friction.

Link
A segment of the bracelet of a watch. Many metal bracelet watches come with removable extension to adjust the bracelet length.

Locking Clasp
the mechanism that secures the clasp in place for fastening to the wrist

Lug
A projection from the case that secures the band to the case. Also called the horn.

Marker
A dashed line or other shape (circle, rectangle, etc.) placed in increments around the dial that denote units of time. Watches can have more than one type of marker to measure different intervals of time. 

Movement
The “engine” of a watch. It’s the inner mechanism that enables the watch to run by enabling it to accurately keep time and perform functions like moving the watch’s hands. Movement is also known as the calibre of a watch.*

Power Reserve
The power reserve indicator is a complication that indicates how much time remains until a mechanical watch needs to be rewound. Mechanical watches only have a certain amount of energy to power all of its functions before the watch stops running. Mechanical automatic watches typically have power reserves of 36-42 hours, and some have power reserves lasting up to 10 days. Power reserve indicators are presented in various designs and positions on a watch. Some are placed on the dial through an aperture or pie illustration, while other indicators are only visible through the case back. Some watches to not provide power reserve indicators at all, but it doesn’t mean that these watches do not possess power reserves. 

Protective Horns
Small projections on the right side of the case that protect the crown

Pusher
A button on a side of the case that controls specific watch functions, such as a chronograph 

Rotor
A flat, usually semi-circular metal weight in a mechanical automatic watch that winds the mainspring to keep the watch powered. The rotor itself is powered by motion of the watch wearer’s wrist. With each wrist movement, the rotor swivels/spins on a pivot and transfers energy that automatically winds the mainspring

Band
A strip of metal, rubber, fabric, or other material that fastens the watch to the wearer’s wrist. Non-metal bands are called straps; metal bands are called bracelets.

Sub-dial
A small dial displayed on a watch’s main dial that provides specialized information not displayed on the main dial, such as elapsed seconds or minutes if the watch is also a chronograph or the date