Hotcold, onoff switch redgreen lights indicate warming or cooling status cools down from 18°c to - 2°c below ambient temperature warms up from 60°c to 65°c by set-point thermostat uses advanced semiconductors to cool and warm up full polyurethane-foam lining without cfc locking latch keeps your items secure and unit insulated operates on dc 12v ( lighter in cartruckvehicle boat ship