Glascribe®
Clips to pocket like a ballpoint pen. Retractable tungsten carbide tip to scribe on glass, ceramics and plastics. Tip included angle: 40°; Shaft diameter: 1.55mm (0.061″); Tip length (angled area): 2.13mm (0.084″); Shaft length from pen body: 4.24mm (0.167″); overall length 133mm (5-1/4″).