With a 100% acrylic outside and a soft 100% polyester inner lining, the Big Bang Theory Soft Kitty Peruvian Cap is great for fans of The Big Bang Theory! The one size fits most Big Bang Theory Soft Kitty Peruvian Cap is based on Dr. Sheldon Cooper's 'happy place song' that allows him to transcend this mortal coil and fill his soul with a deep and penetrating spiritual calm. Why else would you repeat that song over and over again? The Big Bang Theory Soft Kitty Peruvian Cap has two non functional yarn dongles and the agreed upon image of the 'Soft Kitty' from Big Bang Theory goodness! Purr, purr, purr!