Symmetric tongue and t-cross

A set comprising a first panel, a second panel and a mechanical locking device for locking the first panel to the second panel, wherein the first panel comprises a first edge surface and a first panel surface and the second panel comprises a second edge surface and a second panel surface,

• wherein the mechanical locking device comprises an insertion groove at the second edge surface, a flexible tongue positioned in the insertion groove and an edge tongue comprising a tongue groove,
• wherein the flexible tongue comprises a first locking surface and a second locking surface,
• wherein the first locking surface is configured to cooperate with the tongue groove for locking of the first panel to the second panel in a first direction when the flexible tongue is positioned in the insertion groove in a first orientation,
• wherein the second locking surface of the flexible tongue is configured to cooperate with the tongue groove for a locking of the first panel to the second panel in the first direction when the flexible tongue is positioned in the insertion groove in a second orientation,
• wherein the edge tongue is a rod-shaped element at the first edge surface and at a third edge surface of the first panel,
• wherein the mechanical locking device comprises a first element groove at the second panel surface and a second element groove at a third panel surface of the second panel,
• wherein the rod-shaped element comprises the tongue groove and is configured to be inserted into the first or second element groove,
• wherein the first element groove extends from the second panel surface to the insertion groove and the second element groove extends from the third panel surface to the insertion groove,
• wherein the first locking surface of the flexible tongue is configured to cooperate with the tongue groove for a locking of the first panel to the second panel in a first direction which is perpendicular to the first panel surface when it is inserted into the first element groove and the first edge surface is arranged against the first panel surface, and
• wherein the second locking surface of the flexible tongue is configured to cooperate with the tongue groove for locking of the first panel to the second panel in a first direction which is perpendicular to the first panel surface when it is inserted into the second element groove and the third edge surface is arranged against the third panel surface.