Design: This compact ice box is designed to enhance the cooling effect of appliances like air conditioners, refrigerators, and coolers. It features a rubber plug and aluminum cap for leak sealing. The material meets health standards, offering large cold storage capacity and slow release. Versatile Use: Ice blocks Ideal for various applications such as food refrigeration, breast milk preservation, air conditioning ice crystals, nursing cooling, cold transport, and refrigerator power outage cold storage. Ice Crystals: The ice crystals offer a longer time cooling effect compared to regular ice water. They can be reused multiple times for efficient cooling. Easy to Use: Simply prepare an adequate amount of blue ice boxes and place them in the freezer without adding water. After freezing for 4-8 hours (depending on the freezer temperature), remove the blue ice boxes and add them into your appliance's water tank until it covers the blue ice box. Material: Ice packs made from PETG material with dimensions of 4cmx16cm each box package includes six units of small sized blue ice boxes. Specification: MAterial: PETG Size Chart: 4cmx16cm or 1.57inchx6.30inch Package Includes: 6 Ice Boxes Note: Please allow slightly errors 1-2cm differences due to manual measurement.