These are great to wear on ur plate carrier for ruck or run. At the range frozen in 100° heat they last 3-4hrs of keeping me cool. Keeping my core cooler in the heat kept my fatigue down. Keep extra in the cooler to swap out! They will stay frozen in cooler all day.
Dangled 1 in front & rear at Milsim West allowed me to have water on me that wasn't taking up space on my Plate carrier.
These things keep my lunch box cold all day (14hr shifts)! I keep protein shakes & other drinks in my cooler. At end of work day, still cold and have ice in them in the cooler.
Worth every penney!