Unique double temperature-keeping system, this cooler backpack keeps your food cold/warm/fresh. The food grade PEVA liner use heat-welded technology to prevent soft liner leaks, do not worry about melted ice or spilling sauce. Easy to Clean. A super large insulation main compartment specially used to keep fresh meat, fish, cakes and sandwiches, etc. whats more, the rucksack has the side fixing belts specially used to fix the wine and beverages with high bottlenecks.