Very easy to install and sounded good through several different amps. Plug Dia.: 6.35mm / 0.25 inch; Cable Length: 35cm / 13.78 inch. Suitable for guitar, violin, ukulele, mandolin, banjo. Effectively reduces interfering external sounds and is not influenced by sound reflections from nearby objects. Material: Metal Color: Black The sound pickup is a high-quality 27mm piezoelectric ceramic disc transducer. It has a large surface area and can capture a wide range of sound, in case you are unsure where the best sound points are. This is a pre-wired, pre-soldered piezo and jack harness, making installation simple. All you need to do is attach the piezo inside or on your instrument, drill a hole, and mount the jack. Then you're done! Fits most string musical instruments such as guitar, mandolin, violin, ukulele, banjo, etc. Installation instructions: 1. Remove the plastic film from the back of the transducer to expose the adhesive. 2. Place the transducer through the sound hole to the lower part of the front body where the instrument produces the best response. 3. Drill a hole from inside the body, loosen the jack nut, insert the jack into the hole, and tighten the nut. Note: These steps may vary depending on the instrument. Cable length: 32cm Plug diameter: 6.35mm / 0.25 inch Package included: 1 x pickup 4 x gasket 1 x knob Note: Light reflection and different display settings may cause slight color variations between the image and the actual item. Measurement allowance is +/- 1-3cm.