Tollyjoy's Cooler Bag is designed for the modern mom in mind. It is constructed with luxurious microfiber fabric on the exterior and an unique combination of insulating layers within. Included is a contoured refrigerant brick that can snugly fit four 125ml (4oz) milk bottles cold for up to 12 hours. The Cooler Bag is thus convenient for the active lifestyle of moms at play or at work.