These inverter/chargers provide carefree, automatic pass-through of utility current, plus safe, quick 3-stage recharging of your batteries when you're reconnected to shore power! The only inverter/chargers with isobar® surge protection technology. Heavy-duty spike and over/under voltage protection shields your connected microprocessors in PCs, stereos, TVs and microwaves, plus line noise reduction cuts audio static, video �snow� and computer crashes. Why spend extra for less features and protection? Compare the 30-month warranty and price per watt vs. other inverter or generator alternatives�you'll see nobody beats Tripp Lite for value! 1 year warranty. This is a special order item and is not stocked in our store. Please call for availability.