In Ancient Chinese philosophy, Yin and Yang is a concept of dualism, describing how obviously opposite or contrary forces may actually be complementary, interconnected, and interdependent in the natural world, and how they may give rise to each other as they interrelate to one another.This classic mug is made of ceramic. It features the ancient Chinese concept of Yin and Yang in colors of black and white. The mug holds approx. 17 oz.The Yin and Yang mug is fully functional with a pipe and mouthpiece. The pipe is attached to the front of the mug where you can pack your tobacco and light it. Smoke filters up the hollow handle to the mouthpiece on the top. This product is recommended for adult use only. The mug comes in a colored gift box, making a fabulous gift idea to offer to like-minded friends.