They are constructed by individual piezo ceramic sensors for each string to improve string to string balance. Fits for 4-string acoustic bass. Installed under the saddle, with no soldering required.
The Rock Slide Small Polished Brass Balltip Guitar Slide, 17.5 x 57mm - BTRS-SB
Saxophone Leather Pads x 8- Sizes 57mm My Pads
Artec PG-607 55mm x 2.6mm Ceramic Piezo Pickup For 6 / 12 String Acoustic Guitar
Artec PG-617 58mm x 2.6mm Transducer Ceramic Piezo Pickup For Classical Guitar
Artec PG-417 60mm x 2.6mm Transducer Ceramic 4 String Acoustic Bass Piezo Pickup
BAZEITFLOW Saxophone Mouthpiece Protective Cap Large Size 57mm Black – Wind Instrument Accessory for Sax Clarinet Players
