Signage form: The prohibited sign 123b is in the form of a circle, red border, white sign.In the middle is a directional arrow marked by a red line extending from the upper left corner to the lower right corner. Signage materials: Warning sign 123b or many other traffic signs are made of galvanized steel sheet with standard thickness from 1.2 mm to 1.5 mm. Reflective film 3M3900 or 3M610 according to national standard traffic sign.