Derwent Battery Operated Eraser, Artist Tool, Drawing, Art Supplies (2301931) Battery operated eraser includes 8 erasers; requires 2 AAA batteries (not included, Best with Polaroid AAA Batteries) Long-lasting erasers are easy to remove and replace; top-mounted on/off button is perfect for right and left-handed use; comfortable in hand Offering precision and speed the battery operated eraser is just what you need to correct small areas of work quickly **VERY IMPORTANT** NOTE: Refer the Instructional Video before use which is highly recommended.