The FOX 590 DERESPINA CHIROPTERA FOLDING KARAMBIT is just PLAIN SILLY!!!!
A karambit is meant to be a defensive blade so the Emerson, the Spyderco Karahawk, Fox 599, 479, 478 make sense because they can be deployed by the wave simultaneously with extracting them from your pocket.
The 590 has thumb studs (no wave, no spydie hole <-- which you can zip tie wave) so what is the optimal method of deployment?
1) take out of pocket
2) use thumb to...