Stem and light in base of cup light up with white LEDs when switched on Capacity: It's a lamp. Don't drink from it. Materials: Resin and plastic. Batteries: 3 AA (not included). On/off switch on base to preserve battery life. LEDs are not replaceable, but they're LEDs - they should last a long time. Dimensions: 12" tall x 7" across (max). From pet and smoke free environment.