DOUBLE X1-Pro Guitar Pick-up Acoustic Guitar Preamp Professional Preamplifier Soundhole Pickup Magnetic Pickup & Microphone Dual Channel with Volumes Adjustable Reverb Function for 96-104mm Sound-hole It is dual-channel through magnetic-pickup and microphone system combines the humbucking magnetic sound-hole pickup with a condenser microphone to provide a wide ranges of natural sounds adaptable to various performance situations. Volume adjustable design with reverberation function carefully pick the details of every fingerstyle playing board. DOUBLE X1-Pro Guitar Pick-up Acoustic Guitar Preamp Professional Preamplifier Soundhole Pickup Magnetic Pickup & Microphone Dual Channel with Volumes Adjustable Reverb Function for 96-104mm Sound-hole: The cork clip interface makes the installation more convenient and there is no need to worry about the clip opening being too loose and slipping off anymore.Volume adjustable design with reverberation function brilliant tone suitable for various performance situations.Professional custom microphone high sensitivity high sound reproduction low whistle carefully pick the details of every fingerstyle playing board.The exclusive design patent of the rotating battery compartment does not require additional battery packs or battery boxes and the battery can be quickly and easily replaced without loosening the guitar strings which is simple and convenient.Using high-purity self-adhesive copper wire combined with RX winding technology it brings lower noise sound.The coil is no longer expose the sound column and the sound is thicker and more grainy.Simple and novel more ergonomic design brings more user-friendly control-method and more convenient installation experience suitable for install in 96-104mm in diameter of acoustic guitar soundhole. Specifications: Material: ABS Item Size: 149 * 60 * 42mm / 5.87 * 2.36 * 1.65in Power Supply: 2 * CR2032 battery 3V 220mAh Item Weight: 100g / 3.54oz Package Size: 17.5 * 12.2 * 6.1mm / 6.89 * 4.80 * 2.40in Package Weight: 301g / 10.62oz Suitable for: 96-104mm soundhole Package List: 2 * Gasket 1 * Screwdriver 1 * Tail-pin Leather Sheath 1 * Guitar Pick- 1 * Manual (English) 1 * Output Tail-pin 2 * Cable Cleat