I got myself a DogCam Bullet HD Wide a few weeks ago, for use mainly on my road bike. It’s pretty small and attaches very well to my helmet, but alas, it repeatedly crashes when I use it outside. I’ve tried it three times outside now, and each time, it stops recording video at a random point during the recording and the audio changes to a badly tuned radio sound, with massive hissing noises. Totally pointless. I’ve not even taken it anywhere where the terrain is such that it gets knocked around, this has been on roads on a road bike. Not impressed, tbh. I’ll see if I can get a replacement, failing that I’ll chuck it and try something else.