HydraPak UltraFlask+ 500ml vs Katadyn BeFree AC Water Filter (0.5L)
Weight and specs compared for 2026 — and which one to choose.
Compressible 500ml soft flask with an integrated fast-flow filter cap. Built for trail running, fastpacking and on-the-move filtering from hydration vests.
New-for-2025 2-stage filter: 0.1 micron hollow fiber + removable activated carbon. 2L/min flow, 1000L capacity, improved taste.
Building a pack? Add either one to your HikeLoad list, or drop its weight into the base weight calculator, and see what it does to your total weight.
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HydraPak UltraFlask+ 500ml vs Katadyn BeFree AC Water Filter (0.5L): which should you buy?
If saving weight is your priority, the HydraPak UltraFlask+ 500ml wins — at 65 g it is 7 g (10%) lighter than the Katadyn BeFree AC Water Filter (0.5L) (72 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.
See where both rank against everything else in this category on the lightest hygiene page, or browse the full gear weight database.