305mm x 457mm (12” x 18”) in size, which is dictated by the two plates measured together. No. 0-12 + Blank. These units have a black powder coated steel case. The plates are black anti-glare with white numerals The units are operated by pulling a cord at the rear of the steel case, which will in turn flip over the number There is an aperture on the back of the unit to show number displayed on front. The units have fixing plates at the top, which has keyhole slots so units can be lifted off the inside of the board easily.