A flip knife is a type of folding knife, designed to be flipped or flicked into its usable position. Most flip knives have either a thumb-stud or an extended finger guard that acts as a lever, allowing the operator to flip the knife from the closed position to a usable position in a short space of time. Flip knives are sometimes also assisted opening, but they are not automatic opening knives. Due to the desired fast engagement of the knife blade, almost all flip knives are locking, so that the blade does not flip back into the operators knuckles by accident.