A sign alerts customers to their purchase limit on Stanley water drinking bottles at a sporting goods store in Pasadena, California, on January 24, 2024.
  • Stanley's 40-ounce Quencher tumblers are the current must-have accessory among TikTokers and middle schoolers.
  • The brand has been around for over a century, but in recent years it's reached a new market: women.
  • Stanley was the star of #WaterTok and has collaborated with brands like Target and Starbucks.

Stanley cups are everywhere. They've been called "adult sippy cups," the modern version of Beanie Babies, and become a middle-school status symbol.