The Texas Spike is great design.  One of the more popular sellers.  

This Texas Spike has a strong spring and comes out fast with the push of the button.  Handles are black beaded cast.  The spike blade is sturdy 440 stainless with a half serrated edge. 

4-1/2 inches closed and 7-3/4 inches open

comes with a metal pocket clip.

Button is ressesd to prevent opening in your pocket.