Features: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.ABS material and compact size, durable and lightweight, convenient to carry around.Specifications:Material: ABSPower Supply: 1 * 3V CR2032 battery(not included)Item Size: 9.5 * 4.5 * 2.5cm / 3.7 * 1.8 * 1inItem Weight: 33g / 1.2ozPackage Size: 14 * 10.5 * 4cm / 5.5 * 4.1 * 1.6inPackage Weight: 53g / 1.9ozNote:The guitar showed in the picture is not included.Package List:1 * Preamplifier