the Body of Pen is Made of Quality Copper Material, & the Middle Part is Made of Zinc Alloy Material, Which Are Sturdy, Serviceable & Anti Corrosion, Not Easy to Break or Fray, Supporting for a Long Time Use. the Thinking Ball Pen Pen Are Designed with Mini LED Light on the One Side, Which Can Turn on When Youre the Pen, Which Will Emit Charming Light Effect, Suitable as Small Torch, Owing to the Rotating Design, the Pen Does Not Roll Easily to the Ground. Each Fidget Fingertip Pen has a Refill, Which is Quality Ink, Providing You Smooth & Continuous Writing Experiences, & the Ink Can Dry Quickly, Not Easy to Smear or Leakage, Measuring Approx. & the Pen Body is Easy to Detach & Install for Replaceable Refill.