Specification: Material: Metal Size: 11mm/0.43in(H), 8mm /0.32in(W) Color: Chrome Usage: Most Instrument Products Features: 1.Great for existing new items that will fit most used through sturdy Instrument's mounting string 2.Functions: Make instrument strings vibrate more efficiently, improve resonance, increase delay, make sound stronger. 3.Material: Metal material, smooth surface, small size, light weight, professional and practical design, beautiful and generous. 4.Will fit most instrument bodies but please verify the size needed for you before purchasing. 5.Great replacement for your old, broken ferrules. Pack of list:60 x String Ferrules