, high sensitivity and high quality 2 pcs piezo pickup disc transducer into 1 output jack,So that you can stick on your guitar anywhere when you want to play and Golpe Has the advantage of being to interfering external sounds and not be influenced by sound reflections from nearby objects Fit for most string music instruments such as Guitar Mandolin Violin Ukulele Banjo etc. Material: metal + plastic Color: black cable long: 55cm/21.6 inch Plug Dia: 6.35mm/0.25 inch Installation instruction: Take the plastic film down from the back of transducer to expose the adhesive Place the transducer through the sound hole to the lower part of the front body where the guitar produces the best response Drill a hole from inside the body, loosen -pin jack nut, insert it to the hole and tighten the nut Above the procedures for referring depends on different instrument Package Contents: 4 x pickup 4 x glue block 4 x Cable tie 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.