Get your flashing brew cup here. Hoist up a light up mug of beer. Light up barware; Magic Matt's got em'. The on/off switch is on the bottom. Specifications LED Color: 2 Blue, 2 Jade, 2 Red Batteries: Includes 4 Replaceable AG13 Batteries Volume: 16 oz Height: 4.87 in. Width: 5.25 in. Diameter of Brim: 3.62 in.