They are made of graphite material, which can be used long time. Creative in design, but they are practical to use, which will give you a good use experience. Our inkless pencil replacement nibs is is easy to use and can be easily removed and . Features -Color:Black -Material:Metal, Graphite -Size:1.60X0.50X0.50cm/0.63X0.20X0.20in -Made of graphite material, not easy to break, writing smoothly and easy to erase, to use. -These graphite nibs provides you with convenient writing without worrying about ink breaks. -Enough capacity, when you need for replacing new one, this nibs will quickly become your practical helper. -To help you reduce the time sharpening or refilling, we provide you with enough replaceable nibs. -Lightweight and portable, small size is easy to carry and store, and it won't take much space when you store it. Package list: 20 Tips