When preparing for a flight, it’s important to know what I can and cannot bring on board. In your carry-on bag, you can bring personal items such as clothing, electronics, books, and snacks. Liquids, gels, and aerosols are permitted but must be in containers of 3.4 ounces (100 milliliters) or less and fit in a single quart-sized, clear plastic bag. Prescription medications, baby food, and formula are exempt from the liquid restrictions but should be declared at security.