Brand N/A Model N/A Quantity 1 Color Black Material ABS Features Laser alarm device DIY experiment Specification Laser: 5mW; Working voltage: 3~5V; Buzzer: 3V SS8550 Potentiometer; 5516 Photoresistor; Terminal block 7.63-4P Application When the light exposure to the photosensitive resistor the transistor is turned on the buzzer get power and start chirping; When light shines on the photoresistor the transistor stops buzzer power off and stops chirping; The transistors as an electronic switch English Manual/Spec Yes Packing List 1 x Terminal block 1 x 2 -1.5V AAA battery case with switch (14cm-cable) 1 x 2-1.5V AAA battery case without cover (15cm-cable) 1 x 3V buzzer 1 x 5K Potentiometer 1 x SS8550 Potentiometer 1 x Photoresistor 1 x 3~5V Laser head 1 x English user manual