This is the 30-size model of the Topper series, the flagship model of Polar Bear Coolers. It boasts specifications that surpass those of conventional nylon models. Features of this product: Series' strongest insulation structure: Approximately 2.5cm (1 inch) of extremely thick, high-density foam is used. This overwhelming insulation layer provides an amazing ability to keep ice for up to 48-72 hours even in harsh summer environments. Completely waterproof and airtight zipper: Not only does it prevent water leakage, but it also uses a highly airtight zipper that completely shuts out the entry of outside air. It won't leak even if it tips over, making it safe to use in canoes, boats, and camping in the rain. Overwhelming durability (TPU double coating): The exterior uses a material with 840-denier nylon coated with TPU. It is resistant to abrasion on rocky areas and UV rays, and is easy to clean, allowing for professional-grade tough use. Wide opening and large capacity: It has a capacity of 30 cans (approximately 28 liters), allowing you to store large food items and drinks with room to spare. The opening is designed to be wide, making it very easy to put items in and take them out. Specifications: Capacity: 30 x 350ml cans + ice Material