With ink bosses. For 0.35/0.5 mm pens. Contains the most frequently used symbols or symbol parts that can be combined easily for electrical installation DIN 40717, ISO 617. With sine curves and ISO 3098 lettering stencil 3.5 mm extended with Greek letters. Further numbers and arrows in 5 mm plus engineering tools in the form of coordinate scales and 0-90-0° protractor. Row of holes for guidelines and hatching. Material: 1,2 mm green transparent SBS.