Features: Made from hexagonal high carbon steel core, redness coppers, and string beads material, it have good sound quality and stable pitch accuracy. Not easily broken. Easy to install and adjust, suitable for beginners and professional performers. Suitable for all people who love acoustic bass instruments, including students, music enthusiasts, and professional performers. It can be used for personal practice, school bands performances, concerts and other occasions, providing performers with a clear and expressives sound experience. Includes four specifications: 40, 60, 75, and 95, suitable for various acoustic bass instruments. Specifications: Material: Hexagonal High Carbon Steel Core, Redness Coppers, String Beads Packaging Size: Approx. 16x14x2cm/6.30x5.51x0.79inch Package Includes: 4pcs/set Bass Strings note: Please allow 1-2cm errors due to manual measurement, make sure that you not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.