uxcell 3V/5V 12mm Dia Electronic Alarm PCB Mounting Piezo Buzzer Sounder 2 Terminals,complete drive circuit incorporated for direct operation from AC power source. Type : Continuous Sound;Total Size(Terminal Not Included) : 12mmx9.5mm/0.47&#39;&#39;x0.37&#39;&#39;(DxH) TerminalDistance : 7.6mm+/-0.5mm;Materials : Plastic, Metal Just connect to to any power supply from 3V/5V Package Content : 10pcs x PiezoBuzzer