The indicator assembly (or turn signal assembly) houses the flashing amber lights used to signal a turn or lane change. These can be standalone units on the corners of the bumper, integrated into the headlight/taillight clusters, or embedded in the side mirrors. The assembly includes the lens and the bulb holder. It operates via a flasher relay that creates the rhythmic blinking. A functioning indicator assembly is vital for traffic safety; a fast-blinking indicator on the dashboard usually serves as a diagnostic warning that one of the external bulbs in the assembly has burned out.