Maximum operating voltage: 30V Continuous operating current: 2.5A Instantaneous protection current: 3.5A It is designed to avoid the potential short - circuit risk between the positive and negative poles of the battery on the circuit board. Since the discharge rate of model aircraft batteries is extremely high, if there is a direct short - circuit in the power supply part of the circuit board, once the battery is directly inserted, the circuit board catch fire and get charred immediately. On one hand, the circuit board be damaged; on the other hand, there is also a risk of fire. Before powering on the circuit board, insert this protector into the power supply. If there is an actual short - circuit, it immediately cut off the main power supply, preventing the circuit board from catching fire and charred. Its working principle actually makes use of a self - resetting fuse. If a short - circuit exists, the fuse heat up and enter a high - resistance state, blocking the current. After the short - circuit point is eliminated and the actual working current is within the protection current range, the fuse not heat up and be in a normal state. During normal power - on, the green light is on, the red light is off, and the buzzer is silent. In case of a short - circuit, the red light is on, the green light is off, and the buzzer sounds. Explanation of the continuous operating current of 2.5A: When connected to the power supply, it not trigger protection as long as the working current is within 2.5A for a long time. Explanation of the instantaneous protection current of 3.5A: If there is a short - circuit current 3.5A, it immediately cut off the output power supply. Material: Metal + ABS Color: As Shown Package Contents: 1PCS * XT30 Short Circuit Protector Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.