The flash ice cube is made of food grade PS. Batteries are included and installed (but cannot be replaced). The ice cubes do not have the usual on and off buttons but are liquid activated. As soon as you place them into the drink of your choice they will light up and create a fun look for your party theme. Our Liquid Activated Ice Cubes look great as water decorations in Water based Centerpieces, The perfect promo product for a nightclub, restaurant, wedding or private party, have your logo or message light up the night complies with CE, ROHS, LFGB, FDA.