COMPCOOLER Dual Chambers Quick Release Hydration Bladder (2.5 L) 0.40mm TPU with Drinking Tube

Great size and quality. I have the 5, 4, 3 and 2.5L bladder and this one is a nice fit on the standalone cooling backpack. The autonomy is also enough for me. The Weight to cooling duration ratio is nice with the standalone backpack. I really use the cooling feature of the standalone backpack on my way back in the evening when i'm inside the train to keep me cool during hot summer day. I had an issue with the dual chamber, 4 litter bladder. The closing cap had an issue i believe and the water from the middle pouch was leaking. With this one i have no leaks.

Great product and customer service