3dRose 90098_4"Thunder Mountain Scenic Train, Payette River, ID-US13 DFR1213-David R Frazier Two Tone Mug, 11 oz, Black/White Fill with hot liquid to transform from black to white, magically revealing image White ceramic mug with black outer surface; image printed on both sides Microwave-safe, hand-wash to preserve image A perfect gift for any occasion, Fascinate them every time by revealing a secret or surprise image