The product is simple to use—just freeze the ice crystal boxes before placing them in your desired container. Their compact design and efficient cooling properties make them a practical solution for everyday needs, such as keeping meals fresh, maintaining the temperature of drinks, or supporting cold chain systems. Features -Color:Blue -Material:PE -Size:16.00X4.00X4.00cm/6.29X1.57X1.57in -Rapid cooling performance: featuring high efficiency cooling materials, these ice packs quickly lower temperatures and maintain a stable cold environment for hours -Universal application: perfect for cold chain shipping, outdoor picnics, and storage, these cooler ice packs meet diverse cooling requirements with ease -Compact design for easy transport: small and lightweight, these reusable ice packs for coolers are designed for effortless portability, making them ideal for travel and everyday use -Flexible cooling options: the set includes four cooler ice packs, allowing you to adjust the cooling capacity based on the size and type of items being stored -Reusable: designed for repeated use, these ice packs eliminate the need for one-time use cooling methods, promoting practices Package list: 20 x freezer packs