Features： 1、ABS Material: Blind ruler set were made of high quality ABS materials, strong and durable when use. 2、Accurate Data: The scale for accurate measurement is very accurate when learning and measuring. 3、Easy to Use for The Blind: With a bump design, the blind and people with poor eyesight can feel scale by touch. 4、Applicable To: It is suitable for people with poor eyesight and schools for the blind, and can learn measurement related knowledge. 5、Specifications: Including 300 x 15mm blind ruler, 198 x 99mm protractor, 30 degree triangular plate and 45 degree triangular plate. Specification： Item Type: Braille Ruler Set Material: ABS Specifications: Blind Ruler: Approx. 300 x 15mm / 11.8 x 0.6in Triangular Plate: Angle 45 Degree Ruler, Angle 30 Degree Ruler Blind Protractor: Approx. 198 x 99mm / 7.8 x 3.9in Package List： 1 x Ruler 1 x 30 Degree Triangle Board 1 x 45 Degree Triangle Board 1 x Protractor