HydraPak Force (2L Or 3L Hydration Reservoir) - Ultra-Durable Water Bladder for Hydration Pack – Insulated Tube & Dust Cover, Self-Sealing Bite Valve, Leak Proof, Fully Reversible Dishwasher Safe

These are the best hydropack bladders you can get. Fully reversible makes it so much easier to clean and dry. Super durable as well, my old one has taken a few hard hits and never blew open. Their warranty is top notch as well, they will replace a leaking bladder no questions asked.

The tube froze over in the teens (F) overnight during one of my winter backpacking trips, and did not unfreeze until we finished 8 miles later. Nalgene bottles that I had were much more reliable. I’m looking at the specs and details of the case it came in all it says is Rugged and Reliable for Tough Conditions, but no real numbers to indicate the limit of the product. I could have missed something, but I am lucky to have not fully relied on this for my trip.