Doctor Who Mug - Sonic Screwdriver Coffee Cup - Design Changes with Heat - 12 oz by Underground Toys Doctor Who Mug - Inspired by the Doctor's neat gadget, The Sonic Screwdriver Coffee Cup Design Changes with heat - reveals Sonic Screwdriver Phrase: "Those are my ghosts, my past. Every good day, Every bad day." Makes a great gift for any Dr. Who fan or Whovian! Ceramic Material; Hand Wash Only. Holds approximately 12 ounces of hot or cold beverage