From the Manufacturer:
Unique "White Charcoal" pencil allows you to create white areas or adjust values in charcoal drawings. Excellent for final highlights and for drawing on dark or colored papers. Erase with a soft, white eraser. 2 pencils per package, measure 6-7/8" long and feature 3mm wide cores. Includes a metal sharpener. Conforms to ASTM D4236.