Features: 1. High-Grade Material: This lunch ice crystal box contains dry ice crystal particles that are coarse and provide good expansion. The cold retention effect is strong. 2. Easy to Use: Ice crystals in the ice pack for lunch box will expand during the process of absorbing water and freezing, so do not fill to the top when adding water; leave space for expansion. 3. Long-Term Use: During the expansion process, if the ice crystal liquid overflows, the pack can be cleaned and used again. With long-lasting cold retention, it is reusable. 4. Wide Range of Uses: The refreezable ice pack is suitable for food refrigeration, breast milk storage, air conditioning fan cooling, nursing, barbecue cooling, and refrigerated transport during travel. 5. Suitable for Lunch Bags: After receiving the ice brick pack, add water to activate. The ice crystal particles will expand. Once expanded, freeze in the refrigerator for approximately 2–4 hours before use in lunch bags. Notice: 1. Actual color may be slightly different from the image due to different monitor and light effects. 2. Please allow 1–3 cm deviation due to manual measurement. Material: PE Size: 15.8 x 4 x 4 cm Includes: 1 x Ice Crystal Box