Pocket Knives comes in all shapes and sizes and now they come in “legal” speed thanks to spring assisted knives. Spring assisted knives are not “switch blades.” The Huge difference between the two is the fact that in order to open spring assisted knives you have to manually apply pressure to the blade (either the thumb stud or the flipper) while with switch blades it is opened by a push of a button without touching the blade, which in most cases makes it illegal just like the balisong / butterfly knife.
When it comes to spring assisted knives, most people agree that the Kershaw Leek
The Kershaw Blur 1670 features a Sandvik 13C26 stainless-steel blade to hold a strong edged and corrosion resistance. The kershaw blur 1670′s are spring assisted knives with a speedsafe spring assisted system providing a quick draw function
The SOG Twitch XL is one of the great spring assisted knives around. The SOG Twitch XL blade is treated with unique cryogenic heating process , giving it a higher toughness and wear resistance. The SOG Twitch XL handle fit comfortably in your palm.