Alvin - Magnesium Triple-Hole Sharpener - The Alvin Magnesium Triple-Hole Sharpener has unique precision-engineered design that provides a choice of exposed lead length for maximum drawing accuracy and control. Three hole openings: one for general purpose sharpening, one for shaving wood casing only, not lead, and one for sharpening lead only. Replaceable blades. Alvin is one of the primary sources for drafting supplies and drawing equipment in the country. Creative Coldsnow is a pround retailer of Alvin graphic arts, drafting and fine arts products.