Feature: 1. Low Noise: The electric pencil eraser has a noise reduction design, low noise will not disturb your study 2. Large Capacity Charging: The electric eraser is a large capacity charging model, charging for 3 hours, usable for 30 days, 20 times a day, 9 seconds each time, usable for 30 days 3. 2 Refills: The rechargeable electric erasers have two kinds of refills, thick core eraser for daily study and fine core eraser for painting 4. Plastic Collet: The electric drawing eraser comes with a low temperature plastic collet, which is not hot enough to handle 5. Non Slip Design: The electric eraser has a red button non slip design, suitable for small children to grasp, press, and wipe back and forth with a light press Specification: Item Type: Electric Eraser Material: ABS, TPR Function: Sketching, Painting, Industrial Design Battery Type: Lithium Battery(shipped with built in battery) Battery Model: 14500 Battery Capacity: 800mAh Coarse Core Rubber: Daily Learning Thin Core Eraser: for Painting, for Highlighting, for Detailing Charging: Red Light when Charging, Green Light when Fully Charged, Blue Light when Working Product Size: Approx. 2.7 x 16cm / 1.1 x 6.3in. Package List: 1 x Electric Eraser1 x USB Cable1 x Sticker1 x Rubber Sleeve Clip16 x Thin Erasers ( with 6pcs in the Product)12 x Thick Erasers (with 2pcs in the Product) Note: Shipped with Built in Battery