I carry and highly recommend the Kershaw Ken Onion Leek (assisted opener). I have two of them and they, in my opinion, are the perfect SD folder knife.
I also have the Ka Bar TDI, but that is to be worn on the belt.
The Leek can be opened and closed with one hand. (Training on this one-handed operation may require a box of bandaids.

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Stay armed...include a Leek in the arsenal...stay safe!