I make these if you're interested - I usually wear one instead of a bladed Sgian Dubh if I'm out at anything but a very formal occasion and it often comes in very useful

here's an example of a custom made one in Culloden Bog Oak with Sterling Silver fittings, engraved Pictish Wolves and a Sheffield made drop-forged opener:

Safety Sgian Dubhs

I can supply the components if you'd like to make your own.

Regards,
Rab