The Derwent Battery Operated Helical Pencil Sharpener operates on 4 AA batteries (not included). A helical sharpener grinds down the pencil, the steel rotary cutter ensuring the perfect point every time, in just seconds. This sharpener has four rubber suction feet for stability and a transparent shavings reservoir which is easy to empty. It will sharpen up to 9mm diameter pencils. A free cleaning brush is also included.