Resonance guitar-pickup Reverberation/delayl Can be adjusted independently chorusVumber The knob slot is set at your fingertips, making the operation simpler and more user-friendly. Polarized sound hole pickup Improve tone volume No need to drill holes, easy to install and adjust at . the latest sound effect processing chip, reverberation, delay, and chorus have three digital sound effects. High battery and long-lasting battery life:18650 long battery life above 2000ma, usb charging, allowing you to enjoy it all the time. Digital noise reduction The sound quality is more vivid There is a specially personalized double coil pickup between the strings, which has higher sensitivity and reduction. the three low, medium and high frequency eq balanced and freely adjusted, making the melody of the piano more comfortable. No holes required, easy to install The sound hole diameter can be installed within the range of 90-105mm. Same frequency resonance system When not connected to the speaker, you can increase the volume of the guitar by 30%-50%. Colour:Black Material:Plastic + Aluminum Alloy Package Contents: 1 x -APE301 Acoustic Guitar Vibration Pickup Kit(Due to different product batches, the appearance , which does not affect the use) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.