Review on CleverMade Medium-Sized Reusable Ice Packs - Long-Lasting And Convenient Solution For Insulated Coolers & Lunch Bags - Keep Your Food And Drinks Cold Without The Need For Ice - Set Of 4 by Chadwick Webster

Because you add your own water, these ice packs are lightweight for shipping before filling. Once filled, they stay heavy.The powder that comes in them seems to lower the freezing point (more effective) and keep the water from getting funky over time. Unfortunately, it does not make them flexible when frozen. If you need an odd shape, you'll need to keep the ice pack in that shape during the freezing process. The fill cap is an ever-present reminder that these were not sealed from the factory.Filling is easy using the provided collapsible funnel and your own measuring cup. Once filled, they seal securely. I've experienced no leaks.Overall, they are good ice packs that you can have shipped to you economically.Recommended.Review of: https://smile.amazon.com/dp/B0924WMD79?th=1"CleverMade Reusable Ice Pack - Long Lasting Cold Freezer Packs for Insulated Coolers & Lunch Bags - Add Water & Freeze - Clever Ice - No Ice Needed - Size Small - Set of 5"