Abstract: The marker has a pair of upwardly converging reflectant planar panels facing approximately in opposite directions. In its correct attitude on a support surface the panels slope at 2.degree.-6.degree. to the vertical if the marker is intended for assisting the landing of fixed wing aircraft and at 8.degree.-10.degree. to the vertical if the marker is intended for assisting the landing of helicopters (Collectively at 2.degree.-10.degree. to the vertical). The reflectant panels are preferably retroreflectant. Preferably the opposed sloping panels converge when considered relative to intersecting horizontal planes (when the marker is properly levelled). This convergence may also be measured as the angle between vertical planes respectively perpendicular to the opposed panels. Such convergence in plan may preferably be 0.degree.-6.degree. for use with fixed wing aircraft but may be larger for fixed wing aircraft in certain conditions. Such convergence in plan is preferably 16.degree.-20.degree.

Abstract: An edge light marker provides a standard for attachment to an edge light mount with a retro-reflective sleeve slidable onto and off the standard. The sleeve is preferably make of limp constituency and is shaped by the standard.