Features:- Proprietary red copper (pure 99%) coat, anti-rust, 3-4 times longer life than normal strings.- High-carbon steel hexagonal core+ 8% nickel.- Strong tightness offering excellent resonates, extra light tension.- Good feeling, high glossiness, full tone.- For primary guitar players, you deserve strings are in here.Size:- E: 010inch / 0.25mm- B: 014inch / 0.36mm- G: 023inch / 0.58mm- D: 030inch / 0.76mm- A: 039inch / 0.99mm- E: 047inch / 1.20mmType: Acoustic Guitar StringMaterial: Hexagonal carbon steel & Pure copper coatSpecification: Stainless steel, steel core, red copper alloy wound, colorful ball-end.Package Weight : 20 G / 0.71 OuncesPackage Dimensions (L*W*H) : 110*145*7 MM / 4.33*5.71*0.28 InchesRetail Packaging: Yes, Colored BoxPackage Include:1 x Guitar String Set(6pcs)