It’s a freeform circuit that synthesizes sound using 555 timers ... in the form of a RGB LED. One with a self-contained circuit to cycle through various colors and blinking patterns.

This is a small size led flasher built with the 555 timer IC that is powered from 2 x 1.5V batteries. The circuit can be used as a flashing metronome, dark room timer, memo-reminder or other similar ...

They look for all the world like any other LED, though embedded in the plastic dome is an integrated circuit to do all that flashing work ... an LED for over a year using a single C battery.

This voltage-booster circuit for driving one or more white ... where K is a constant that depends on the particular type of 555 timer used. The LED's peak current is roughly equal to the maximum ...

The 555 timer is a versatile integrated circuit (IC) that can control timing in electronic circuits. It's one of the most widely used ICs due to its reliability and flexibility.