Not the modern bobby pin.
发簪 is the long single-stick hair ornament - often jade, silver, or wood - that holds an entire bun in place. In imperial times, a girl's coming-of-age ceremony was called
笄礼, 'hairpin rite', because she received her first
簪 at fifteen. A staple of
汉服 (Han-style dress) revival outfits today.
