Set of panels with a mechanical locking device

A set of panels comprising a first panel with a first main plane with a first main surface and a second panel with a second main plane with a second main surface, wherein the first main plane is essentially perpendicular to the second main plane in a locked position, wherein the second panel comprises a third main surface at a first distance (A) from the second main surface,

• wherein the first panel and the second panel comprise a locking device for locking a first edge of the first panel to a second edge of the second panel,
• wherein the locking device comprises an edge groove at the first edge of the first panel, said edge groove comprises a first groove surface and an opposite second groove surface and a first bottom surface,
• wherein the locking device comprises a tongue groove at the second main surface of the second panel,
• wherein the second panel comprises a first edge surface which is facing the first bottom surface in a locked position, the second panel further comprises a second edge surface extending between the tongue groove and the first edge surface,
• wherein the edge groove comprises a tongue, which is configured to cooperate with the tongue groove in a locked position, for locking the first and the second edges in a first direction which is perpendicular to the first main plane,
• wherein the first groove surface cooperates with the second main surface, at a first contact area in a locked position and the second groove surface cooperates with the third main surface, at a second contact area, to lock the first and second panel in a second direction which is perpendicular to the second main plane,
• wherein the first contact area is positioned, in a locked position, at a second distance (H) from the second contact area,
• wherein the second distance (H) is greater than the first distance (A),
• wherein the edge groove at the intersection of the first and third main surfaces has an open space,
• wherein the tongue groove comprises a tongue groove surface, wherein the tongue groove surface comprises a guide chamfer, such that the guide chamfer intersects the second main surface, wherein the guide chamfer provides a guide surface at a smaller angle relative to the second main plane compared to the tongue groove surface.