Route marker for Expressway 4 (E4) the route designation for Subic–Clark–Tarlac Expressway (Subic to Mabalacat segment) and Subic–Tipo Expressway.
Sign dimensions from Highway Safety Design Standards: Part 2 : Road Signs and Pavement Markings, page A78
Department of Public Works and Highways, Hushskyliner and HueMan1