Description:4 bands EQ-7545R pick-up equalizer system perfect for standard acoustic guitar or cigar box guitar. Curved plastic surface matches the curved side of a standard acoustic guitar.4 bands (bass/mid/treble/presence) plus volume control, built-in battery holder for 9-volt battery (not included), low battery indicator. The piezoceramic pick-up rod offers great tone and pickup range and is designed to be mounted under the saddle of a standard acoustic guitar, but can be easily built into a guitar bridge cigar box. Pre-wired for easy installation, connecting cable with 6.35mm(1/4 inch) output jack. Size Chart:Size: 22x14x5.5cm/8.7x5.5x2.2inPackage Included:1 Set 4 Band EQ CorrectorNote:Please allow 1-3mm measurement deviation due to manual measurement. Due to the different monitor and light effect, the actual color of the item may be slightly different from the color showed on the pictures. Thank you!