Suction cup phone holders are devices designed to securely attach smartphones to smooth surfaces, such as car windshields or office desks. They use a suction mechanism that creates a vacuum seal, allowing the holder to stay in place while providing easy access to the phone. These holders are popular for hands-free use, navigation, and video calls. Most suction cup phone holders are adjustable, accommodating various phone sizes and angles. They are typically made from durable materials like plastic and rubber, ensuring longevity and stability. Many models also feature quick-release mechanisms for easy removal and reattachment of the phone.