The Tombow Mono Smart Plastic Eraser, available here on Amazon, is an eraser costing about $3, and can be purchased at cheaper prices at Tombowusa.com. It is a small white eraser, 5.5 mm wide, and is intended for precision erasing. It works very well for erasing small chunks, and is significantly better at erasing words than shaded areas or drawings. It thoroughly gets rid of pencil marks when new, but as the corners and edges dull from use, the erasing quality becomes worse and worse. It stays in the same area of how much it erases, but it very slowly deteriorates. It never erases downright badly, though. It is not at all good eraser to use for erasing large amounts of pencil, so if that is what you are looking for, this eraser is not for you. Since it is small in width, the eraser goes away fairly quickly, so one large mark you choose to erase could leave you with 3/4 of the eraser. The white plastic eraser comes in a cardboard case, which protects the body from being damaged while you are erasing, and, frankly, looks good. You do have to press down relatively hard to get the best erasing from this product, which is never a positive thing. Overall, I give this eraser three and a half stars, because although it erases small amounts of pencil marks very well, it is used up much too quickly, and it deteriorates over time. I do recommend this eraser for the price, but if you get them and intend to use them for a while, get them in bulk here on Amazon.