It appears to be only water. It doesn't say specifically. But I think for the price and thier slenderness in combination with thermal type lunch bag/pale they can the meet the needs of most people.
By Runningoutofspace on February 18, 2015
I don't think they would last 9 hours. I use all 4 ice packs with an insulated bag. I even put the bag in the fridge the night before and pack the ice packs before leaving. I've found them still cool after 5 hours, but not enough to help the food.
By Chantal on July 3, 2014
Fit & Fresh Lunch On the Go comes with a single cooler pack that is approximately 7.5" x 4.75" x 0.25". Each pack in the "set of 4" in your picture measures 4.75" x 4.75" x 0.25". I hope this answer was helpful.
By creazyb on May 20, 2014