Why do I have .SEC files? (YI LITE Action Camera) .SEC files are much lower in bit-rate which allows you to quickly preview videos on the app. Related articles How do I download videos and photos from the app?(YI LITE Action Camera) When I playback my videos on the computer, What happened that the sound sometimes is lagged or no sound at all? And why I have trouble in playbacking the videos sometimes? (YI LITE Action Camera) How do I upgrade the YI LITE Action camera firmware version? What is a .thm file? Where can I find my Camera DID number?