This is a video player with a high level security function to prevent unauthorized access to content. When initializing the device or changing the device while using the application, a conflict with the existing registered device ID may occur. In this case, you need to contact the customer center of your eLearning site to request initialization of the device ID manually. 【Main features】 1. Speed ​​control : 0.6x ~ 2.0x 2. Display aspect ratio: 4: 3, 16: 9, full screen 3. Gesture (brightness, volume, fast forward, rewind, play) 4. A- B repeat playback