1Set Yootones Pickups Piezo Transducer, 3 in 1 Microphone Contact Self-adhesive Mono Piezo Pickup with Buzzer Compatible with Electronic Acoustic Guitar Violin Ukulele

3 in 1 transducer pickup system is compatible with most string music instruments, amplify an upright bass, banjo, violin, ukulele, viola, cello, mandolin, resonator guitar, etc. The plastic squares is a self adhesive block to mount the extra wire in your box, without pre amp they will work well. Small size, portable and easy to use. Cable Length: approx. 31.5cm, 3-pack Piezo electric Disk Dia. : approx. 27mm, Endpin Jack Dia. : approx. 6.35mm, Endpin length: 63.5mm. This is a passive pickup, No Battery and Soldering Required, pre-wired piezo mic save time for you, easy to install, convenient to use. The advantage of being able to eliminate interfering external sounds and not be influenced by sound reflections from nearby objects, give it a purer acoustic tone.