Uni NanoDia Color Erasable Lead Refill 0.5 mm
The Uni NanoDia pencil lead incorporates nano-diamond into each lead to enhance the strength and quality of the lead, and smoothness of the writing. In conventional lead, graphite particles are in close contact. The friction of the particles reduceds the smoothness of the writing. By injecting nano-diamonds between graphite particles, the friction is reduced and the smoothness is increased.
Note: The mix set includes 20 leads of all seven colors: Blue, Green, Lavender, Mint Blue, Orange, Pink, and Red.