This Kokuyo 54-corner triangle eraser is an extremely innovative design. Instead of only 8 corners which a traditional rectangle eraser has, the greater number of corners makes erasing finny details easier. This high-quality eraser offers much more precision usages than many other products. It makes you feel there is always a sharp end to provide the accuracy you need. Also, it come with a triangular plastic case allowing you to rearrange the small pieces of erasers in any order you prefer.