Features Better Learning: Electric bell is used in school physics teaching to explain and demonstrate the mechanism and working principle of DC electric bells. Combined with the air extraction device, it can also be used for air sound transmission experiments. The Using Tips: The voltage should not be too high and the continuous power on time should not be too long. If the contact point of the vibration fragment is in poor contact with the contact screw, the oxide layer on it can be wiped off with sandpaper. How to Store: The electric bell has been debugged and inspected before leaving the factory. Do not disassemble or move the parts randomly. After use, please put it back into the box and place it in a dry and non corrosive gas free place. Simple Operation: Connect the two terminals to a 4‑6V DC power supply with a wire, connect the power supply, and the bell will sound. The Adjustment: During the experiment, if the vibrating shrapnel does not work properly, the distance between the contact screw and the shrapnel can be adjusted to allow it to contact and leave normally. Specification: Item Type: Experiment Electric Bell Material: ABS Working Voltage: DC 3-6V Resistance: The electromagnetic iron coil has a DC resistance of 10-20 Ω. Sounds: When the electric bell is working, the ringing tone is clear within a range of 15M. Work Environment: Environmental Temperature: -10-40℃ Relative Temperature: No more than 85%.  Package List:1 x Experiment Electric Bell Package List 1 x Experiment Electric Bell