features 6mm arm diameter, 9mm threaded collar internal diameter, it is designed for Floyd Rose tremolo bridge, with this arm, you can quickly adjust the string tension and change the tone, realize tremolo effects. Features: Tremolo arm for electric guitar, special for Floyd Rose tremolo bridge. 6mm arm diameter, 9mm threaded collar internal diameter. Made of high quality iron, high glossiness. Arm length approx. 175mm. It helps you to easily adjust the tension of string and change the tone.