The Black & Decker BEW230BCA heritage mouse sander has a detailed base which is designed to give better results when sanding intricate areas. The tear drop shape of the base allows you to access tight corners. It has a rotatable base so you can rotate the paper as it wears, extending the life of the sanding paper. Quick fit sanding paper for faster sanding action and easier paper fitment.Tear drop shape allows access to tight cornersRotatable base to rotate paper as it wearsRubber grips for comfort