An Albert chain is usually attached to what

Watch
A pocket watch (or pocketwatch) is a watch that is made to be carried in a pocket, as opposed to a wristwatch, which is strapped to the wrist.

They were the most common type of watch from their development in the 16th century until wristwatches became popular after World War I during which a transitional design, trench watches, were used by the military.

Pocket watches generally have an attached chain to allow them to be secured to a waistcoat, lapel, or belt loop, and to prevent them from being dropped.

Watches were also mounted on a short leather strap or fob, when a long chain would have been cumbersome or likely to catch on things.

This fob could also provide a protective flap over their face and crystal.

Women's watches were normally of this form, with a watch fob that was more decorative than protective.

Chains were frequently decorated with a silver or enamel pendant, often carrying the arms of some club or society, which by association also became known as a fob.

Ostensibly "practical" gadgets such as a watch winding key, vesta case or a cigar cutter also appeared on watch chains, although usually in an overly decorated style.

Also common are fasteners designed to be put through a buttonhole and worn in a jacket or waistcoat, this sort being frequently associated with and named after train conductors.

Read more...https://en.wikipedia.org/wiki/Pocket_watch