Cameron Diaz & Leo DiCaprio Tout TAG Heuer at AMNH

Posted Sunday November 11, 2012 10:32 AM GMT

Walking the red carpet in support of her new signature item, Cameron Diaz attended the launch of her limited edition TAG Heuer signed watch at the American Museum of Natural History in New York City on Saturday (November 10).

The "Bad Teacher" star let the product shine in a simple strapless knee-length black dress and matching heels as she joined alongside fellow brand ambassador, Leonardo DiCaprio .

Recently, 40-year-old Miss Diaz decided to try her hand at another venture, writing. She's working on a fitness book, but clarifies, "It's not about what I eat or do what I do. It's really about the information, so that young girls and women can look at it and make their own choices."

Instead, she says, "I'd hate to give them guidelines of what I do... I'm excited about my discipline [which revolves around] a protein, a grain and a green... I want to be disciplined. It's not a limitation to me; it opens up my life to so many opportunities."

Photo Credit:, Getty Images