This 7mm (17/64") long stainless steel teardrop shader is a versatile pen for shading, smoothing, separating and cleanup. Gets under small raised feathers to clean up underneath them. Also excellent for heat transfer of photocopied patterns onto almost any surface (wood, gourds, paper...). Will only work with the Binding-Post Interchangeable-tip Pen #BPH. Heavy duty cord is recommended.