Braille Geometrical Device is an excellent learning tool for blind students who wants to learn about geometry, mathematics or engineering. It has a rubber mat, a compass, a ruler, a protractor with swing-arm, spur wheel & two triangle shaped rulers, all with small dots depicted in Braille. All its pieces are heavy duty, sturdy and well made. Braille Geometrical Device is beneficial not only for blind students but for students with normal vision as well.