For technical pen Uni nano dia ul05-102nd (0.5) 2B

One lead contains 400 million nanodiamond particles (needle crystals) resulting in smooth, clear printing without the lead breaking. The performance of these leads is superior in quality to anything available on the market. Black graphite reinforced with oils with a lubricating effect gives smoothness to the graphite, enabling stronger pressure on the paper and giving you a soft feeling when writing. It reduces the kinetic friction between the paper and the lead and enables vivid, clear print lines. One tube contains 12 leads. Lead diameter: 0.5 mm. The price is for one tube, commercial packaging is 12 tubes.