Lens cap for SJ4000 camera (GoPro lookalike)

I designed this because other lens caps I had used tended to fall off leaving the lens exposed. This one will clip on securely and will not come off unless you want it to.

It is designed for the SJ4000, which is a low cost copy of the GoPro.
It will probably also fit a GoPro but I don't know for sure because I don't have one to try it on.