Material: steel, with rustproof coating for durable use; Length: each is approx. 90 cm/ 35.4 inch String diameters: 1: 0.2 mm/ 0.007 inch; 2: 0.3 mm/ 0.01 inch; 3: 0.6 mm/ 0.02 inch; 4: 0.7 mm/ 0.027 inch; 5: 1 mm/ 0.039 inch; 6: 1.2 mm/ 0.047 inch Suit for: colored are helpful for the guitar beginners to remember and practice; Also fits for guitarist to make their acoustic guitar look beautiful and awesome Color: Picture color Material: Steel Package include: 3 Set of Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.