Under saddle pickup piezo usually used for acoustic guitar resonance pickup.
Durable materials, can be very good pick up guitar sound, can be a good removal of noise, so you enjoy the music to bring happiness.
This is a rod-style piezo, made to be installed beneath the saddle of a standard acoustic guitar as a pickup device.
Simply build it into your bridge, or mount it inside the box under the bridge with glue, and you'll be amazed at how much better it picks up the full range of tone when compared to a small disk.
Material is software, you can bend and not be damaged, so you more long-term use.