This type of machine platforms differs from the others primarily by the construction, which is metal.
This makes the structure more resistant to environmental conditions at the workplace.
Metal system type "M" are designed for making platforms of a relatively small height, ie in the range of 10 ÷ 25 cm.
Compared to wooden "L" and "P" platforms for which Hmax = 15cm, the height of "M" type platforms can be higher (even 25 cm),
which can be important at some work stations when operating machine tools.