One of the original hydration system brands, the Platypus Big Zip Hoser uses three-layer laminate to add extra durability, while the taste was among the best. The bite valve can be locked closed to prevent drips. The zip opening allows easy cleaning and filling, and it survived our 20kg test. But there are no suspension loops, so the hydration system can move around easily. This adds to nervousness about the zip closure system, which may be accidentally opened more easily than other designs.
Materials: 3-layer laminate with PU lining
Capacity: 2 litres
Made in Ireland
Stores in UK: England 300; Wales 30; Scotland 50; Ireland 20
Verdict: Buy it if you trust the Big Zip to work no matter how much the bladder moves around.