Polar Tech RE-FREEZ-R-BRIX RB30 Foam Refrigerant Packs, 31oz Capacity (Case of 6)

Stays cold for a very long time. In the description the height and width should be swapped. The width is the one that is 4 inches. I hesitated buying this because I thought it was 4 inches thick. It didn't seem right so I had to go on their official website to get the correct dimension.

Love these! Great way to keep items cool without the worry of ice melting and making a mess. I originally had a couple which were a much larger size. I used them for years but they eventually broke down. The larger size was difficult to find and very expensive. I bought these and vacuumed two of them together with my vacumn sealer to form a large one. Voila a large one! Works great and now I have 2 different sizes; kept some as the small single size.

These are great! 4 kept an insulated shipping box good and cold for 2 days... by the 3rd day it was getting more 'cool' than cold but it didn't ever get warm.

I use these in my lunch bag for work. Sits on my desk all day and the block is still cold when I get home.

We use these daily and they are remarkable! They last a long long time and keep their cold for hours.

We love these bricks! Much better than the mess from ice. We bought them to take to wine country to make sure our purchases didn't get too hot. Worked perfectly! Lasted two days.

worked perfect to keep cold what needed to be kept cold in cooler and even Rubbermaid totes. better than ice since didn't melt and things weren't sitting in water.

Glad we bought this product!!