Kepo piezo elements for audio transducers kepo ft 50t 30a1 481 the keno piezo element 500 o 3 05 khz is a 50mm diameter piezo element with a 30000nf30nf capacitance that can be used for a small audio transducer such as a buzzer kepo ft 50t 30a1 481 piezo element 500 ohm 3 05 khz 50mm