A road tripper's best friend, the Wagan 2084 is a personal cooler/heater powered by your car's cigarette lighter socket. Craving frosty sodas and fresh fruit in the summertime? No problem. Taking a hot dinner to a chilly autumn football game? This is just the ticket. Like other portable 12-volt coolers, this one operates via "the Peltier effect", in which electricity makes one side of a metal plate cooler than the other. The advantages over a regular fridge are numerous: --no moving parts --no potentially-toxic or ozone-depleting refrigerants --no bulky radiators or compressors --unit can operate on its side or upside down In addition, the cooling/heating process is reversible. With the flip of a switch, the unit goes from cooler to heater. The device is not a substitute for an ice chest or a microwave -- its cooling powers are limited to 45 degrees below the surrounding air temperature, which is plenty for an air-conditioned car, but don't expect to store ice cream if it's 90 degrees inside the vehicle. Likewise, the heater is able to reach a temperature of 140 degrees, but its heating ability is limited; it's great for keeping a potluck entree piping hot, but heating a frozen burrito would take hours, not minutes. For operation at deskside or in a dorm room, an AC adapter is available.