Control buttons: power switch, bass adjustment, volume adjustment, treble adjustment Product Matching | A pair of 26 inch passive speakers. Supports connection to mobile phones, computers, MP3 players, and set-top boxes. The amplifier supports a 12V power supply. The specification of the power plug is 55X2.1mm. If not used for a long time, be sure to unplug the power to avoid unpredictable malfunctions or safety issues. Input voltage: DC12V 2A Rated power: 20W x 2 Maximum support power: 100W () Frequency response: 20HZ-20KHZ : 85db Product matching impedance: 4-16 Ω Output channel: 2.0 stereo sound High pitch control: 12dB ± 10KHz Low frequency control: 12dB ± 100Hz Signal frequency: 220MV 47K Output port: anti falling four position wiring clip Audio input port: stereo (Lotus) (supports connection between computer, phone, MP3, etc.) Due to different batches, there may be differences in product appearance and printed text, which not affect use Colour:Black Material:ABS Package Contents: 1x Amplifier 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.