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 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 download videos and photos from the app?(YI LITE Action Camera) What is loop recording? How do I edit photos and videos within the app?(YI 4K+ Action Camera) Why are the photos and videos distorted on the margins?(YI LITE Action Camera)