The Rapidograph work sets with pen stations keep your technical pens ready to draw instantly. The ideal horizontal position and a flexible double seal prevent the pens from drying. Individual pen stations can be taken from the set and affixed to a table or drawing board with double-sided tape (provided with the work set). All sets include compass attachment for 3.5/4mm dia. and stencilling joint. College 4 Pen Set Contains: 4 Rapidograph pens (0.25mm 0.35mm 0.50mm And 0.70mm) 12 hi-polymer HB leads B20 eraser 6 ink cartridges 1 compass attachment.