Kepo piezo elements for audio transducers kepo ft 31t 13a1 472 the keno piezo element 500 o 13 05khz is a 31mm diameter piezo element with a 50000nf30nf capacitance that can be used for a small audio transducer such as a buzzer kepo ft 31t 13a1 472 piezo element 500 ohm 13 05 khz 31mm