material: Includes 4 rotating pens. Both sides are made of heavy metal steel balls for greater stability, stronger gyration force and better dynamic balance, the pen body is designed with aluminum alloy dynamic balance support ring , symmetrical balance points to help practice, flexible fingers, exercise brain vitality. .: The rotary pen, beautifully designed, comfortable to hold and with non-slip, anti-slip and wear-resistant coating, TPR thermoplastic rubber nib, shock-resistant and shock-absorbing. Cross-diamond-shaped embossing, beautiful design , ABS resin body, high hardness, strong and durable, professional rotary pen. .Practice: This pen is very suitable for office workers and students, and it is very useful for thinking, learning and anxiety. This professional rotary pen has a symmetrical axis. The professional rotary pen is suitable for professionals and beginners.A better gift: Using a rotary pen can help develop children's intelligence, test finger flexibility, and bring people more fun. It is suitable for both children and adults. A great gift for office workers and students. .Satisfactory Service: We want to provide efficient service to our customers. If you have any questions, please feel free to , our customer service team will contact you within 24 hours. .