波兰采购需求：旅行包、背包、斜挎包

I'm looking to develop a portable USB beer dispenser that can efficiently keep beer cold while serving it. In Georgia, there's a popular trend of buying 5-liter beer bottles for outdoor activities like picnics and barbecues, but the downside is the beer heats up quickly, which nobody enjoys. The device needs to fit a 48 mm neck for these bottles, and the pumping mechanism has to ensure a balanced flow rate—fast enough to pour without excessive foam but slow enough to maintain the beer's quality. Additionally, incorporating a cooling feature is crucial to ensure that the beer stays cold throughout the dispensing process. The entire setup should be USB-powered, compact for portability, and cost-effective for consumers.