Q-Connect Shatterproof Ruler with measurements in millimetres and inches. 30cm (12). White. This 300mm white ruler features inches on one edge and mm/cm on the other. Quality white plastic construction won't deteriorate, allowing you to measure with precision. Perfect for technical drawing and shatter-proof to prevent accidents. The twin-use scale lets you measure and plot in both metric and imperial measurements. It features a bevelled edge that provides increased accuracy when measuring by shortening the distance between scale and paper. Sturdy white acrylic provides durability.