Mini Preamplifier Preamp 6.35mm Plug with Bass Treble EQ Volume Control for Acoustic Guitar: It can also turn your home stereo into a guitar amplifier allowing you to experience the pleasure of performing.preamplifier with impedance matching function for acoustic guitars.ABS material and compact size durable and lightweight convenient to carry around.6.35mm plug for connecting musical instrument and 6.35mm output jack for connecting guitar amplifier.Supports 2-band EQ(BASS & TREBLE) and adjusting. Specifications: Package Weight: 53g / 1.9oz Item Weight: 33g / 1.2oz Material: ABS Package Size: 14 * 10.5 * 4cm / 5.5 * 4.1 * 1.6in Supply: 1 * 3V CR2032 battery(not included) Item Size: 9.5 * 4.5 * 2.5cm / 3.7 * 1.8 * 1in Note: The guitar showed in the picture is not included. Package List: 1 * Preamplifier