Description: 【Premium Material】: The Voltages Sensitive Relay is made from premium PP and metal, ensuring wear resistance, durability, and long term use 【Voltages Sensitive Relay Double Battery Kit】: A voltages sensitive relay allows two batteries to be charged from your engine alternator at the same time. When your engine is on and the start battery is sufficiently charged the isolator kit will begin charging the second (auxiliary) battery simultaneously 【Zero Voltages Drop】: When the voltages of the start battery drops the isolator kit disengages from charging the auxiliary battery. This isolates the start battery and eliminates the possibility of draining it, ensuring that you always have enough charge to start engine 【Weather Resistance】: This double battery isolator is also built to withstand extreme weather environments and shock, and is water resistant. It is safe for use even for your vehicle needs in dust, wet, and unexpected extreme weather environments 【Wide Compatibility】: Suitable for ATV, UTV, Boats, RVs, Campers, etc Specification: Nominal Voltages: DC12V Intermittent Current Rating: 140A Combine / Open Voltages: DC 13.3V/12.8 Continuous Current Rating: 125A Size Chart: Package size: 17cmx12cmx6.5cm/6.69inchx4.72inchx2.56inch Package Includes: 1 Voltages Sensitive Relay Note: Please allow slightly errors 1-2cm differences due to manual measurement.