Check the listing for details. Rock Hard Coated Stainless Steel Guitar Pick Silicon Straight Grip. Condition: New. Listed at 19.99 USD. Rock Hard Silicon Straight Grip - Single Pick Rock Hard picks are scientifically engineered with a combination of precision metal-finishing and diamond nanotechnology. Picks are manufactured from high-grade stainless steel, electro-polished and then vacuum coated with a layer of chemical vapor deposited (CVD) diamond-like carbon (DLC). The DLC coating on the surface of Rock-Hard picks was originally developed for night-vision optics used in military aircraft, vehicles and portable thermal imaging systems. The material is a dense, extremely hard form of amorphous carbon which possesses many mechanical and thermal properties of its crystalline sibling,CVD diamond. Because of the hardness and amorphous nature of DLC, the nano-coating is highly wear resistant and conforms to all of the imperfect structural inconsistencies in a polished metal surface. So the coating actually makes a polished metal surface even smoother. In addition,the coating has virtually NO FRICTION (more slippery than Teflon), so there is no metal-on-metal wear when it's pressed and dragged continuously against guitar strings. The result is an extremely hard surface that doesn't wear, and will not abrade the metal it's rubbing against, e.g. guitar strings. Have a question about this item? Please send us a message . . We work very hard to maintain our high positive feedback rating. If for any reason you are unhappy with your purchase, please contact us before leaving feedback so we can attempt to remedy the situation.