internally illuminated solar studs pavement marker-Nokin Road . The Culley Marker is, in fact, a Delineation Device, an Internally Illuminated Raised Pavement Marker ( IIRPM ), a Solar Powered, LED, Road Marker. With a low profile of only 16.1mm and diameter of 120mm, Culley Marker is a fully autonomous, solar-powered, transparent, safety device, benefiting all road and pathway users. Quote Now. heavy duty solar road markers with 6 safety locks South