Sensitive sound board, copper coil magnetic pickup Noise class A, all discrete line drivers Very stable feedback Passive / active switch Frequency response: 20 Hz to 20 KHz Color:Black material: metal Loudness control Sound control Calm atmosphere Adjustable rod piece for perfect balance and smooth threadless top Overall Class A discrete preamplifier line driver provides superior performance with no noise. The center-to-center distance between the center of the mount hole when picking up the mount is about 10.5 cm Package Contents: 4 x Magnetic Pickup for Guitar Only the above package content, other products are not included. Note: Light reflection 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.