Very easy to install and sounded good through several different amps.Plug Dia. : 6.35mm/0.25 inch; Cable Length(Approx.) : 35cm/ 13.78 inch.Suitable for Guitar Violin Ukulele Mandolin Banjo Cigar box Guitar.With the advantage of being able to eliminate interfering external sounds and not be influenced by sound reflections from nearby objects.Material:MetalCOLOR:blackThe sound pickup is high-quality 27mm Piezoelectric ceramic disc transducerIt is very and can collect a wider range of sound in case you are not where are the best parts of the sounds.This is a pre-wired, pre-soldered piezo and jack harness which make it easy for you. All you have to do is to attach the piezo in or on your build, drill a hole and mount the jack. Then you're done Fit for most string music instruments such as Guitar Mandolin Cigar box Guitar Violin Ukulele Banjo, etc.Installation instruction:1 Take the plastic film down from the back of transducer to expose the adhesive2 Place the transducer through the sound hole to the lower part of the front body where the guitar produces the best tonal response3 Drill a hole from inside the body, loosen -pin jack nut, insert it to the hole and tighten the nutThe above procedures depend on different instruments.Cable long : approx 32cmPlug Dia: approx 6.35mm/0.25 inchPackage included:5x pickup20x gasket5x knobOnly 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.