These high quality leads are formulated under an exclusive process to improve strength yet retain blackness and smoothness. Achieve dark, clean lines with the slightest pressure. Super Hi-Polymer formula reduces the risk of lead breakage and consequently saves lead. Details:BlackHB pencil gradeFits 0.5 mm mechanical pencil30 pieces of leadProduces fine linesStrong and durableReduces the risk of lead breakage Packaged in protective plastic tubesPolymer lead