Prompter for someone forgetting pulling-out key

The utility model discloses a device used to prevent people from getting out of the key. The utility model comprises a lock core and a control circuit. The technological characteristics are that: a marble (4) is arranged on the rotating sleeve (6); the fixed sleeve (7) matching with the rotating sleeve is provided with a special marble (3), a spring (2) and a jiggle switch (1); the spring (2) is arranged between the special marble (3) and the jiggle switch (1); the jiggle switch (1) is connected with the control circuit; a block board which is used to prevent the spring (2) from touching the keyboard of the jiggle switch (1) is arranged under the jiggle switch (1). The utility model is simple in structure and has high reliability and durability.