I bought these to replace one that I’ve used for about five years that sprung a leak. I use them often taking food to pot lucks at church in a food carrier. They work great!Great for keeping those dishes hot or cold when going to a pot luck dinner or to a friendI have used the packs for both keeping a casserole hot, and a salad cold. They easily heat up in microwave, or put in freezer to use cold. They fit nicely under a 9" x 13" casserole dish.I keep a Coleman cooler in the back of my SUV year round. Iced in the summer, hot in the winter. Now during COVID-19, I occasionally go pick-up takeout food because our Governor said we can't eat in restaurants. Most restaurants I visit are 10 - 20 minutes each way, so I need to keep the food warm for the return trip. It's so disappointing when you spend a lot of money for take-out food and you get home it's cold. I just bought a couple of these packs a week or so ago, and I've used them a few times. Heat them up, throw them in the cooler before I go, and the food is nice and warm when I get back home from the restaurant. I'm not going 5 stars for one reason, I wish they had some kind of slip cover, like nylon to protect the pack. I probably can find or make something that would work. Wish I knew how to sew. Otherwise, great product!Works well so far for heating and coolingProduct has instructions for heating the pads with your home microwave. Followed these with the first one and it ruptured/exploded before complete! Cleaned up (easier said than done) - successfully heated the second pad following the same instructions... Be warned. JerryThe plastic pack seems fragile and easy to break. we always handle very carefully. do not understand why not use other materials, or enclosed in a cloth bagI like that it can be either a cold or hot pack, exactly what I wanted