I had the original chilli tech camera until it fell off and died. Didn’t find it very good for quality. They have now brought out a new improved version which should be a lot better. The previous handlebar mount was no good They are hd. They do a 4k version but in that mode the battery life is seriously reduced. They can be fitted on a helmet which is probably better. They were promoting a new one which I think was front and rear view , but it seems to be sold out. They are cheap. https://www.chilli-tech.com/
Apart from that I imagine the go pro is the best, though very expensive and when I last looked, not particularly good battery life.
