Great for night time play, the rainbow ball lights up and flashes LED lights in rainbow colors. It is extremely sensitive to movement and includes an on/off switch. Turn it on and this fun toy begins to flash in bright colors. After a few moments of inactivity, the long-lasting LED's will stop flashing, but the slightest motion of this cat toy will activite it again. The fun cat toy ball measures approximately 13 centimeters in diameter.