This Super Hi-Polymer lead refill produces crisp lines of consistent darkness, smoothness and density in 0.9 mm Pentel pencils. The mechanical pencil refills feature HB hardness, which is equivalent to a No. 2 pencil, and is excellent for all general writing, including items to be faxed, photocopied and electronically scanned. The 0.9 mm thick lead is perfect for young writers and first-time users of automatic pencils. Each super-strong lead writes as far as an entire wooden pencil and produces a dark line.