ZUMER BMT1212H09
It is a transducer without an internal generator,
Type: Electromagnetic audio indicator / buzzerOperating Voltage: 7V to 16V ACResonant Frequency: 2.4 kHzSound Output: 85 dBDimensions: Diameter of Ø12 mm x 9 mm heightMounting Style: Through-Hole Technology (THT / Pins),