Not a 4K Camera !
Conclusions: Sensor used (OV4689) is not 4k, only half of that. The sensor size is 2688x1520 pixels or roughly 4MP, which is very close to a 2k (2704x1524) resolution, by far not 4k.
4k requires a resolution of 3840x2160, or a sensor size of roughly 8MP. So the 4k claim is based on an artificial "upscaled/interpolated" figure. Basically false advertising.
In actual video tests it compares well to my 1080p SJ4000 cam, but it does not do significantly better.