Abstract: An insert is adapted to be inserted in an undercut T-shaped slot extending horizontally along an exposed surface of a panel, the undercut extending parallel to the surface and including an opening extending between the undercut and the surface. The insert is formed of resilient material having a foot adapted to be extended into the undercut and a pair of opposed legs which extend through the opening when the insert is positioned in the T-shaped slot, the legs providing between them an opening communicating with the foot. The legs have flanges on their outwardly extending ends which flanges face away from each other and are spaced outwardly away from the surface of the panel on opposite sides of the slot when the insert is positioned in the slot.