Just like your fridge light at home, the Coghlans cooler light will illuminate the inside of your cooler so you can quickly find what youre after. Light turns on automatically when the cooler is opened and shuts off when the cooler is closed. Light will turn off after 20 sec. even if the cooler is not closed completely to save battery power. Great for coolers, tackle boxes and toolboxes. Includes 3 LR44 1.5-volt button-cell batteries.