This CS09 sports camera has ultra clear 4K image quality and synchronous recording function. This camera requires a high-speed memory card to be inserted in order to function properly. If you do not have a high-speed storage card in your hand, you can choose the option with a storage card. The video recorded by this camera is played on a computer and requires a computer screen. For example, if your computer's screen resolution is lower than 2K, the visual effect will naturally not achieve the expected effect. But watching on mobile applications is not affected.