The Spring Assisted EDC (Everyday Carry) spring assisted knife is large enough to fit comfortably in the hand, keeps blade length between 2"- 4", and is sturdy enough for daily use while fitting comfortably in the pocket. This blade length / spring assisted combination keeps them legal in nearly all municipalities making them perfect for everyday carry and use. Compared to it's push button cousins these knives are opened by pushing an index-open "flipper" or thumbstud. Once the blade has reached an opening angle of 30-40% an internal spring will assist in the opening causing the blade to slam open with the same force as a switchblade.