The D-TAR Sadducer Under-Saddle Transducer for Steel String acoustic guitar uses 6 discrete piezo crystals, one for each string. Discrete piezo crystals have better string-to-string balance and offer increased responsiveness to your guitar top's vibrations for great tone. The result is a high-output pickup designed for even frequency response. High output response eliminates the need for expensive on-board signal boosting electronics.
The D-TAR Sadducer is exceptional for melody players, especially guitarists who play over the entire fingerboard. But perhaps the biggest benefit is that, unlike other piezo pickups, the Sadducer has lower output impedance and does not require a built-in or off-board preamp to boost and smooth the guitar's signal. That means no batteries required.