This stretchy soft clear ring contains 3 incredibly bright red, green, and blue LEDs that will dazzle you with their brilliance. Move it around and watch the fast flashing strobe leave awesome light trails. This is definitely very different from those cheaper blinky rings you see around. The one-size ring stretches easily to fit most fingers. Just push the ring to turn on and again to turn off. Long-life button cell batteries are enclosed and are NOT replaceable.