Kepo piezo transducers 15 to 35hz kepo kps g5211 k622 the kepo piezo transducer 1535hz is able to generate an audible siren tone when energised by a 12vdc rated voltage and 616vdc operating voltage outputs of up to 105db at 12vdc100cm can be achieved suitable for use in professional commercial and industrial applications kepo kps g5211 k622 piezo transducer 15 35 hz 52 mm