Features: The surge suppressor can protect the vehicle electrical systems to avoid damage from voltage spikes while starting welding or jumping. Suitable for 12/24V systems. Polarity protected-reverse connection warning. Designed for across battery terminals installation to absorb unnecessary power surges. LED Lights: Green light on means protection on, red light on means protection off. In conditions of no protection, the warning alarm will sound too. Please feel free to contact us if you have any questions, we will try our best to meet your satisfaction. Specifications: Voltage: 12/24V Material: Metal, Plastic Color: Multicolor Weight: 650g/22.9oz Size: 28*10.5*6cm/11*4.1*2.4in Package List: 1*Surge Suppressor