End links in watchmaking refer to the components that connect a watch bracelet to the watch case. They come in two main types: solid and hollow. Solid end links are crafted from a single piece of metal, providing a robust and secure fit. They are heavier and offer a higher quality feel, as they sit firmly in place without any movement. This construction makes them less flexible but more durable, often preferred for their premium appearance and stability.

Hollow end links, on the other hand, are made from thinner metal that is folded to form the link. This design makes them lighter and more adaptable, allowing for slight adjustments to fit different watch cases. Historically, hollow end links were common in vintage watches and are sometimes favored for their ability to be bent for a better fit. However, they may not provide the same level of sturdiness as solid end links, potentially leading to more movement and noise. Each type has its advantages, with solid end links being ideal for those seeking durability and a solid feel, while hollow end links offer flexibility and a lighter weight.