1.Smart 3-pack Design for different requirements. [Large (11"), Medium (9"), Small (6")] - The small ice pack is perfect for children, or smaller aches and pains, while the two larger ones are great for teenagers and adults. 2.Fast Relief - Ideal for application of cold therapy to help reduce pain and swelling from minor scrapes, bruises, muscle aches, sprains and strains. Recommended to help relieve pain, reduce swelling, and speed recovery. Stays cold much longer than gel packs or other cold packs. Suitable for sport injury and first aid. 3.Superior Leak-resistant Cap with large cap opening to allow for easy filling of ice cubes or crushed ice. 4.Very Simple To Use - Simply fill with ice and water to relieve discomfort from headaches, bruises, migraines, muscle aches and swelling. For heat therapy, add hot water (not boiling, Notice: The temperature for hot water therapy is 50-60/122-140.) to help soothe an upset stomach, migraine, sinus and joint pain. 5.A Must-have Product - Keeps a handy ice bag in your work desk, car and home for grab-and-go comfort from pain. Whether you are experiencing the weekend hangover, headache or aching and soreness from a recent visit to your chiropractor, get the soothing relief from hot or cold therapy right away.