Sonitron Buzzer 12V
Some of ther have been used, but testet OK
Choose between
Type: SM4, Diameter: 23 mm, 2 pins
Type: SM2, Diameter: 32 mm, 2 pins
Type: SAT-1050, Diameter: 29 mm, 2 pins
Can be used with Arduino. Buzzers can be found in alarm devices, computers, timers and confirmation of user input such as a mouse click or keystroke