Thomann ACM-01, Accordion Tone Pickup System, 2 Treble and bass condenser microphone 1, Polar pattern: Omnidirectional (for installation in the accordion), Frequency response: 50 to 19,000 Hz, Max. SPL: 135 dB, Treble / bass controls, Jack-Out, Power adapter (9V), Includng assembly instructions (Velcro strip is glued on the inside under the treble and bass top and the microphones - which also have hook and loop connection - attached) and feeding adapter (9V)@+@+*Note:* The battery is not included