Fangrui Product Details Mini Preamplifier With Impedance Matching Function For Acoustic Guitars. Supports 2-band Eq(bass Treble) And Volume Adjusting. 6.35mm Plug For Connecting Musical Instrument And 6.35mm Output Jack For Connecting Guitar Amplifier. It Can Also Turn Your Home Stereo Into A Guitar Amplifier, Allowing You To Experience The Pleasure Of Music Performing. Compact Size, And , Convenient To Carry Around. Power Supply: 1 X 3v Cr2032 Battery(not Included) Colour:red Material:aluminum Alloy Package Contents: 1x Guitar Preamplifier 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. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.