Qurly's Magic Color Changing Morning Hot Coffee or Tea Light up Mug - Ceramic Heat Sensitive Cup (12 Ounce) Materials: High-quality porcelain. 12 ounce capacity. Water temperature should be over 70C/158F,the light bulb will be turn on. The surface painting of the mug is made of organic matter. Mug paintings sustain well with hand wash. No microwave. No high temperature. No direct sun exposure. No high heat of dishwasher. Do not scratch the mug with metals or hard substance Safe to use it daily and environmentally friendly. Non-toxic and lead free and chrome-free. Meets all FDA standards. Slowly add hot water/hot milk/hot chocolate/coffee/tea/ to the mug, you will see the light bulb lighting up! Perfect for gift for your family and friends.