This thorough video created by Triple M on YouTube will help you take first steps with your new DR900S-2CH dashcam paired with the Power Magic Ultra Battery.
The reviewer goes over every detail, making the video an excellent choice for first-time BlackVue owners. The video goes through a descriptive unboxing, setup (installation of both front and rear cameras, as well as the Ultra Battery), majority of the settings in the BlackVue app as well as a comprehensive review and footage samples.
The entire video is 4K (although YouTube compression slightly decreases the image quality, you should still be able to appreciate some of the details shot with a 4K DR900S-2CH on your 4K monitors).
Watch the video here or by clicking the thumbnail above.