Pentel Ain Stein Mechanical Pencil LeadDurable Mechanical Pencil LeadPentel is a pioneer of graphite lead research, and Ain Stein is their most recent lead innovation. As leads get softer and darker, they often get weaker; conversely, as they get harder they often become scratchy and difficult to write with. But not so with Ain Stein. Thanks to an innovative molecular ceramic frame which holds the lead together firmly from the inside, these leads are now about 10% stronger than Pentel’s original refill leads, and still just as smooth to write and draw with, even the harder grades. The leads are supplied in handy plastic swivel-top tubes and are suitable for all Pentel mechanical pencils.92% recycled content40 refill lead per tubeIt is standard lead used in all automatic pencils Ceramic cell structure is 10% stronger than other Pentel leadsThe lead has achieved dramatic improvement in strength and smoothness