Battery operated eraser. CONTENTS - 1 Battery operated eraser (Uses 2AA Batteries, not included) . 7 White replacement eraser(2.1 cm x 0.4 mm) . 3 Grey replacement eraser (2.1 cm x 0.4 mm) 4 Plastic tubes . FUNCTIONS OF WHITE ERASER - Used to erase out writing by graphite pencils without smudging. Erases precisely. Can also be used to erase from films. Selective highlights can be created in already existing drawings, e.g. signature can be added. Can also be used to polish things and remove dirt from them without damaging the objects. FUNCTIONS OF GREY ERASER - Grey soft sand eraser may be used to erase pen writings and print marks of inkjet printer. Can also be used for manicure and polishing objects. Grey eraser is used to erase on resistant based materials. It can grind out the rust layer on the contact points of certain electrical devices at home or factories. Auto erasers for artist drawing , sketching , Drafting , Architectural plans , Art and crafts , Battery operated Pencil eraser , Pen , Printing marks eraser.