Uni Shift Pipe Lock Drafting Pencil 0.3mm Light Blue Accent & Strength & Deep & Smooth Uni 0.3mm HB Top quality Diamond Infused Leads [Nano Dia-16 Leads] & Pencil Eraser for Shift (Set of 5)Value Set Tip storage" and "knock lock mechanism" It is smooth and they are a spare lead which cannot break easily, and the profitable set which attached Nano Daia &5Pencil Eraser(hot product of Uni) together Finger does not slip, Roulette grip Because the center of gravity in the distal direction, the ease of writing stable