PREMIUM MATERIAL: Made of high material, durable and lightweight to carry and storage. MULTI-FUNCTION: It can contact microphones sound by having direct contact with the , which can effectively eliminate external sounds interference and not be influenced by sound reflections from nearby objects, offering a better tone sound. TO INSTALL: Easy to install and removable -adhesive design allows you anywhere on your instrument, and never harm to the surface of instrument. WIDE APPLICATION: Fit for string music instruments such as acoustic guitar ,violin ,mandolin ,banjor etc. Perfect accessory for DIY CD of players. The Guitar Piezo Transducer is durable and lightweight to carry and storage. It can contact microphones sound by having direct contact with the , which can effectively eliminate external sounds interference and not be influenced by sound reflections from nearby objects, offering a better tone sound. Specifications: Material: Metal Color: Black Length: 30CM Sensor Diameter: . 2.7 cm / 1.06 inch : 1/4 inch (6.35 mm) Weight: . 10 g Included: 1 x Guitar Transducer 1 x Nut 1 x Gasket Installation instruction: 1 Take the plastic film down from the back of transducer to the adhesive. 2 Place the transducer through the sound hole to the lower part of the front body where the guitar produces the tonal response. 3 Drill a hole from inside the body, loosen -pin nut, insert it to the hole and tighten the nut. Above the procedures for referring depends on different instrument Only the above content, other are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.