Suitable for surfaces mounted Piezo Pickup This machine is a JFET high impedance type amplifiers circuit, which is not affected by the length of the input line and have no frictions effect The builts-in lithium battery is rechargeable and can last for 10 hours on a single Gains: When the capacitance value of the Piezo Pickup is 10nf, it is about 20db,The lower frequency limit is 30Hz Input impedance, 10MΩ Size:. 65x63x24mm/2.56x2.48x0.94inch Charging Interfaces: TYPE C DC5V Input/Output:6.35mm 1/4TS Output Impedance:600Ω Colour:Black Material:ABS Package Contents: 1 * Chip Piezoelectric Pickup 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.