Kepo piezo elements for audio transducers kepo ft 27t 40a1 470 the keno piezo element 200 o 4 05khz is a 27mm diameter piezo element with a 25000nf30nf capacitance that can be used for a small audio transducer such as a buzzer kepo ft 27t 40a1 470 piezo element 200 ohm 4 05 khz 27mm