Holster for the Rinke Onyx?

[LGman072]

Any ideas for a decent, snug fitting holster that I can use with the Rinke Onyx on my V20?

I got this one on Amazon:

https://www.amazon.com/gp/aw/d/B01M...UacUvbUpU5537070#immersive-view_1477938047107

But although the Onyx fits in it, it's too loose of a fit. It would slide out an drop on the ground unless its mostly upright. I don't want to worry about my new phone falling out every time I bend over or squat down.