Set of panels, a method for assembly of the same, and a locking device for a furniture product

A set comprising a panel, an adjacent panel and a locking device, wherein the panel comprises a groove and at least one hole connected to the groove via an opening, wherein the adjacent panel comprises a first edge which is configured to be arranged in the groove of the panel, wherein the locking device is configured to lock the first edge of the adjacent panel in the groove of the panel, wherein the locking device comprises a cylinder and a lever connected to the cylinder, wherein the cylinder is configured to be arranged in the hole in the panel, wherein the cylinder is configured to be displaceable in said hole between a mounting position and a locking position by means of rotation of said cylinder, wherein the cylinder comprises a locking surface configured to engage with the adjacent panel by means of a rotation of said cylinder for locking the adjacent panel to the panel, wherein the cylinder comprises a mounting surface configured to be arranged adjacent and/or facing the opening in said mounting position, wherein the cylinder comprises a first width and a second width in a plane transverse to a longitudinal centre axis of the cylinder, wherein the first width is parallel to the mounting surface and the second width is transverse to the mounting surface, wherein the first width is greater than the second width, wherein the second width is configured to be perpendicular to the first edge in the mounting position, wherein the locking device is configured to be rotated past a position in which the first width is perpendicular to the first edge and to the locking position, and wherein the lever comprises a lever locking surface, wherein the lever locking surface is configured to cooperate with the adjacent panel in the locking position.