The mechanical unit come in 2 sizes 228m x 305mm ( 9″ x 12″ ) or 305mm x 457mm ( 12″ x 18″ ) which is dictated by the two plates measured together
There are 2 sets of numbers available dependant on your requirements
They come as No. 0-9 + Blank or 0-12
These units have a black powder coated steel case with anti glare and 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