Piezoelectric Ceramic Ring 10*5*2 https://www.bjultrasonic.com/shop/5pcs-1052-ring-piezoelectric-ceramic/ Piezoelectric Ceramics (piezoceramics), such as Piezoelectric Ceramic Ring, Piezoelectric Ceramic Disc, Piezoelectric Ceramic Tube, Piezoelectric Ceramic Ball/Hemisphere, Piezoelectric Ceramic Cylinder and Piezoelectric Ceramic Square/Rectangular.