Thumb Studs make knives easier to open. They allow for the blade to be opened up with the thumb. The stud may be placed on one or both sides of the blade; some models have a thumbstud on the spine. Depending on the production process, the thumbstud can be secured with a rivet or screw. Knives with screwed thumbstuds can be easily retrofitted for ambidextrous opening without compromising their look and design.