Keep a replacement Gel Ice Pack for your Willow Portable Breastmilk Cooler on hand so you're ready to pump on the go at a moments' notice. Designed to remain separate from your milk to prevent potential contamination and make cleaning a breeze, the ice pack is conveniently built into the cooler — no ice cubes necessary! (It's TSA compliant, too.) Willow Portable Breastmilk Cooler sold separately.