These drawing leads are divided into two types - 2mm lead by Turquoise for leadholders and Pentel fine mechanical pencil leads that never need sharpening. Made from a mixture of graphite, clay and polymer, these leads resist breakage. Choose Pentel leads in .3mm, .5mm, .7mm, and .9mm. Film leads are also available for drafting on mylar. Special 5.6mm leads from Cretacolor fit their holders and are large enough to allow free form sketching and drawing in grand scale!