The string locking nut is special for 4-string electric headless bass, zinc alloy material offers it well durability, it helps to tightly lock the string. Features: High quality 4-string electric headless bass string locking nut. Tightly locking the strings. 39.2 * 26mm(L * W), approx. 31mm string spacing. Made of zinc alloy, anti-corrosive and durable. Supplied with 2 wrench and 2 mounting screw, easy to install. Specifications: Material: Zinc Alloy Suitable for: 4-string Electric Bass Color: Black Item Size: 3.92 * 2.6cm / 1.5 * 1.0in Item Weight: 65g / 2.3oz Package Size: 4 * 2.6 * 3.5cm / 1.6 * 1.0 * 1.4in Package Weight: 66g / 2.4oz Package List: 1 * String Locking Nut 2 * Wrench 2 * Screw Note: Please check the detailed size shown in picture carefully.