7 section equalizing adjustment Range: +-12db, 60HZ, 150HZ, 400HZ, 1KHZ, 3KHZ, 6.5KHZ, 15KHZ, Composed of TI or ST TL074 Preamplifier Gain: 4580 classic operational amplifier provides 5x amplification (14db); The amplifier part of the Earphone adopts the 47 type earphone driver circuit composed of NE5532, Which can drive all types of earphones; Input impedance 20K, output impedance 600 ; The 3.5mm input interface supports a 4-pole plug, and the output is connected to a headset with a microphone. Normal voice calls can be made on the mobile phone. Another terminal with a lotus interface is available; Power Supply: Between DC5V-12V, the interface Specification is 5.5 x 2.1. The Static Current of 5V Power Supply is about 390ma, and that of 12V Power Supply is about 140ma. Power Can be supplied with a power bank or a high-quality charging head There may be AC sound when the charging head is powered Color: As Shown Material: plastic+metal Package Contents: 1 x Host 1 x USB DC cable 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.