Features: Reliable Material: These rulers are made of smooth inlaid acrylic, which is serviceable enough to use for a long time and can easily satisfy most needs of people. Ideal Gifts: The transparent t shape ruler would be a good helper for people who often need to draw or draft, it is a nice gift to engineers, architects, students, draftsmen, artists and so on. Specifications: Material: acrylic Color: cleear, black Size: 18 inch, 24 inch, 36 inch Package includes: 3 x T Square acrylic rulers Notes: Manual measurement, please allow slight errors on size. The color may exist a slight difference due to different screen displays.