The mark is a configuration of a wall access panel assembly consisting of a frame surrounding a window opening and having a raised peripherally extending wall forming the boundary of the window opening where the wall has symmetrically slotted groves facing the window opening, said assembly further consisting of a panel member covering the window opening where the panel member has integrally formed truncated locking pins projecting from the periphery of the panel with the truncated portion engaging the slotted groove to releasably lock the panel to the frame.
The lining is a feature of the mark and is not intended to indicate color.