The Hunter style pocket watch has a metal lid to cover and protect the face of the watch, with a spring hinge that is operated by pressing a button, usually in the crown. It is designed so that fox hunters could open their pocket watch with one hand whilst holding the reins of their horse in the other hand.
With a glass window in the lid the watch can be read with the lid closed; this is called a Half Hunter pocket watch. A large [pocket watch with a skeleton dial and a window in the back cover is called a Double Hunter pocket watch.
A classic Hunter watch. It has a chain loop attached to the crown.