This is a roller stamp or rolling stamp.
It is a less common type of stamp. Under the clear cap there is a wide 'wheel' with a raised pattern. You roll this wheel on the ink pad, then roll the stamp along whatever paper you want to stamp on, leaving a trail of designs until the ink runs out. This is used for page dividers, page borders and sometimes to roll across envelopes for decoration.
Usually, the design the stamp makes is represented on the handle. Is that the case with this stamp? Its unknown unless someone stamps it and sends it in.