HenryDa 6 Pieces Reusable ice Packs for Coolers,Long Lasting Cooler ice Pack, 24to 48 Hours of Cold Gel Ice Pack.Lunch Bag CoolerIt can Hold 1400-1600ml of Water

I gave 5 stars because these appear to be exactly the same as the branded higher expensive ones. Only negative: There were NO INSTRUCTIONS! The only info I saw on packaging was to put in refrigerator to cool, huh? I went to the listing for the name brand one which were exactly the same size and I was able to find that I needed to pour exactly 3.5 cups of water into each, burp the extra air out, place the blue stopper and tighten down the cap. It also said to allow them to lay out at room temp about 30 min. to completely gel before putting into the FREEZER. That makes more sense. The test is today and I will write a follow up about how long these stayed frozen. I'm mailing a package with frozen food today that will be delivered by end of day tomorrow. I bought a small insulated bag that I will slip two of these in along with a few frozen food items and it will be zipped and then placed into a box with some other stuff. These are supposed to stay cold 24-48 hours. so we shall see! UPDATE: I packed up the box at 9am Mon and kept in house until UPS picked up at 3:30 pm. Package arrived Tues at 7 pm. Items were no longer frozen but very cold. The ice pack lived up to it's 24-48 hrs claim. I would definitely buy again.

I put mine in the freezer and the chill in my insulated bag is fantastic! Product says refrigerate, but the chill factor just wasn’t cold enough for me.

I was going on a 22 hour flight and needed something to keep my food cold while it was in my suitcase. After 22 hours in a plane and walking around the airport for 5 hours. When we got to our hotel room they were still frozen I never saw something worked so well in my life.

I thought I could flatten these between uses, but once you add the water it mixes with their freezing agent. So it takes up a ton of freezer or fridge space.

These last a long time in frozen state. Highly recommend them.