A component inside a mortice lock which acts as a detainer. The lever is a flat piece of metal which swings on a pivot. It has a gating cut out of it at different heights to suit the step cuts on the key. When the gates all line up by use of the correct key, the lock bolt is allowed to throw by the action of the key. Generally the greater the number of levers in a lock will result in a greater number of key differs and a higher level of security.