Come and Check Our Promo Solutions.This picnic cooler backpack is made of polyester with large capacity can hold anything, laptop, work materials, clothes, etc. It can also be used as a mobile food preservation room with an independent heat and cold insulation layer for storing food. There is also a USB socket on the side for charging. It is a great choice for your business trip, outdoor travel, sports and daily work. Pls check inventory and detailed info with us before placing your orders.