These tub shaped pencil sharpeners are designed to sharpen your pencils quickly and easily with a minimum of mess. They feature metal sharpener inserts, hinged covers to prevent shavings from spilling, and lids with safety locks to avoid accidental opening ings.Single-hole sharpener has one sharpener for standard-sized graphite pencils up to 8.2 mm. in diameter.Double-hole sharpener has two sharpeners, one for standard-sized graphite pencils up to 8.2 mm. in diameter and one for thick graphite and colored pencils up to 10.2 mm. in diameter.