Our cooler does not need to be plugged in. It is a portable heat preservation box, which is both cold and warm. Product name: Insulation box/refrigerator Shell material: PE Inner wall material: food grade PP Insulation: EPS Product color: blue, orange Holding time: 6 hours (at constant temperature) Refrigerating time: 48 hours (at room temperature) Product capacity: 27L Product weight: 2.7kg Correct use of incubator 1. Try to avoid direct sunlight in the insulation box. 2. Minimize the number and time of opening the lid. 3. Fill the insulation box as much as possible. 4. Try to freeze or refrigerate the food in advance. 5. Configure enough ice brick ice packs or ice cubes.