1. MATCHING FUNCTION: Mini preamplifier with impedance matching function is suitable for acoustic guitars 2. 6.35MM PLUG: Used for connecting musical inst ents and 6.35mm output jack for connecting guitar amplifiers 3. ENJOY THE SHOW: You can also turn your home stereo into a guitar amplifier, so that you can experience the fun of music performance 4. plastic: plastic material is compact, strong and , light weight, easy to carry, very convenient 5. GIFT FOR MUSIC LOVERS: This is an important music inst ent accessories, can be used as a great gift for your kids, friends or music lovers Item Type: Guitar Pre Amplifier Battery Required: 1 x Button battery CR2032(not included) Colour:Red Material:plastic Package Contents: 1 x Guitar Pre 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.