Double G0 Guitar Pickup Resonance Pickup Electric Bass Guitar Preamplifier Coil Soundhole Pickup with Chorus Delay Reverb Effect Preamp and Effects System for 96-104mm Sound-hole Sound hole vibration pickup with reverberation chorus and delay effect. Cork pad clamp no damage to paint of instrument. Unplugged with DSP reverberation effect. Using the same frequency resonance system to amplifies the guitar s sound 30~50%. Magnetic coil microphone and phase independent adjustment. Sound hole installation no need drill hole easy to install. Ergonomic design more humanized control. The same frequency vibration technology can efficiently release the sound effect of DSP chip so that the guitar can have reverberation chorus and delay effects without plug-in and external effector. Specifications: Material: ABS Package Weight: 485g / 17.11oz Package Size: 17.5 * 15.2 * 5.5cm / 6.89 * 5.98 * 2.17in Suitable for: 96-104mm soundhole Battery: 3.7V 2000mAh Packing List: 1 * Pickup 2 * Gasket 2 * Clip 1 * Tail Nail Leather Cover 1 * Vibrating Horn 1 * Cable 1 * Screwdriver 1 * Output Tail Nail