Review on ROCKRAIN Hydration Bladder: Premium 2/2.5L Leak Proof Water Reservoir for Fitness Enthusiasts - Ideal for Running, Hiking, Cycling by Jerardo Phi

I bought the 2 liter and it fits easily in my medium camelbak backpack and stays in place. The bite valve works very well (has a cap and hood to prevent leakage), the snorkel is insulated which keeps the water cooler and provides comfort if the snorkel (unintentionally) rubs against your skin. This often happens with every blister. I will buy it again when I need replacements for my large backpacks. I would suggest a 2.5 liter size (more value for the dollar). The bubble itself is thick and I think it will last quite a while.