Usage Tips:12V, 140A, 13.3V cut-in voltage, 12.8V cut-out voltage,; Package Include All the Bits and Pieces Needed for a Complete Installation Working Voltage: Having Voltage Sensitive Chip,Rely Cuts in at 13.3 Volts and Cuts out at 12.8 Volts to Ensuring Primary Battery is Always Ready for Vehicle to Run. Fuction:Like Having Two Separate Power Sources,The Dual Battery Isolator Kit Enables Your Accessories to Run From a Separate Battery While the engine is not running on your vehicle While keeping your Main Battery Charged and Your Vehicle Always Ready to Go and Start When You Want It. Compatibility: This battery isolators are small and suitable for almost anywhere, for ATV, UTV, Boats, RV's,marine vehicle, truck, caravan Colour:Black Material:Plastic + Aluminum Size:7x7x5.3cm Package Contents: 1 * Battery Isolator Only the above package content, other products are not included. Note: Light shooting 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.