Slide bracelets were the result of the advent of the wrist watch. The slide was a piece that attached to a watch chain, and once pocket watches fell out of favour, the little jewelled items were collected and made into bracelets.

This example from New York Estate Jewelry uses slides from the 1940s, when they were made specifically for this decorative purpose. It features various gem set slides and is 14k gold. It is priced at USD$5,100.