According to an example aspect of the present invention, there is provided A gripper comprising a body (1), the body (1) comprising an attachment (12) to a holding body. There is provided a first gripping jaw (2) extending from the body (1) and comprising a concave groove having has two longitudinal opposite edges (4, 5)； at least one second gripping jaw (7) having a second concave groove with two longitudinal edges, at least one longitudinal edge of the second longitudinal groove being attached to one edge (5) of the first longitudinal groove either pivotably or detachably； and at least one closing element (10, 11) for pressing the second gripping jaw (7) towards the first gripping jaw (2).
