COMPCOOLER Single Chamber Quick Release Detachable Bladder (3.0L) 0.40mm TPU

Keeps me very cool in the warm Arizona heat. Easy to use. I suggest only freezing about 2.0L of water instead of filling lithe bladder to the line. Light weight and easy to don.

This is a replacement for the original order. The first one developed a pin hole leak on a seam after about 10 uses. We'll see if this one lasts a bit longer.

This thing keeps me ice cold in a 100 degree attic for 2 hours then I have to change the bladder.

Only wish I found out about this sooner