Alvin 14" professional parallel glider ruler. Easy-to-use parallel glider combines the functions of a T-square, triangle, transparent straightedge, and protractor in one. One of the most useful and convenient aids you will ever find for drafting, drawing, and nautical applications. Smooth gliding action to easily make parallel lines without twisting or turning under accidental pressure.
Features durable clear acrylic plastic blade with printed graduations, throughholes at 1/2" increments for drawing circles. Ruling edge in inches (reading to 16ths) or in metric. Comfortable aluminum roller bar with non-skid rubber O-rings for smooth operation and firm grip on most any surface. Includes complete instructions. 14" Alvin 296 parallel glider.