This ruler is made from extruded plastic (1000 x 60 x 10mm) with a magnetic rubber-sheeting strip running down the back and plastic handle on the front.
This holds the ruler firmly against the whiteboard and stores it out of the reach of young children.
The ruler clearly shows the connection between centimeters and millimeters.
The printing is large so it is also a visual teaching aid.
NT-3013 Magnetic Whiteboard Metre Ruler