Advantage：This cool pens can not only make you the focus of the crowd,,pen spinning can also help to train your hands, eyes and cerebellum at some certain. Size：The size of cool pen is about 8.7 inches long, black ink, tip 0.5 mm round. Material：This spinning pens is made of plastic, which is safe and durable. Applicable population：For students looking for cool stuff, this cool office supplies is a good choice. This product is suitable for men, women, boys and girls, especially for unicron fan. This will be an exquisite cool office supplies. Customer service:If you encounter any problems after receiving the stationery pens, please contact us in time. We will reply to you within 24 hours and solve the problem for you.