Alvin - Constant 2mm Drawing Leads 3 pack - 4H - The Alvin Constant 2mm Drawing Leads are top-grade imported 2mm refill drawing leads, superior in both quality and strength. Alvin Constant 2mm Drawing Leads are uniform in texture and time-tested under rigid standards. Drawing Leads can be used with any standard lead holder. Supplied in a 3-pack tube. 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.