HydraPak
HydraPak Flux 1 L Flexible Bottle
- Weight for its size: 8/10 How much it adds to your pack for the water it holds.
- Packed size (empty): 8/10 How much room it takes up when it is empty, for the water it holds.
Lowest price we found
£25.99 at Ultralight Outdoor Gear
Go to Ultralight Outdoor Gear Compare 3 shopsHikers who want a 1 L bottle that stands up on its own but rolls up when empty
- Type
- Soft
- Capacity
- 1 L
- Weight
- 102 g
- Packed
- Not published
Where to buy
Ultralight Outdoor Gear £25.99 In stock. Free delivery. Shop shows RRP £27.99. Free tracked UK delivery on all orders (header: free over £15).
View at shop: Ultralight Outdoor GearSportsshoes £27.99 In stock. Delivery £4.99. Standard+ 48 UK delivery £4.99 on its page. Its site-wide 15% code is not included in the price.
View at shop: SportsshoesHydraPak £28 In stock. Delivery £3.60. Mammoth and Golden Yellow in stock at this price; Sage Green is out of stock. Free UK delivery over £50 (its shipping policy page says £75); below that £3.60 Royal Mail Tracked 48 or £6.00 DPD next day.
View at shop: HydraPakPrices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Weight for its size
From maker's figures 8/10How much it adds to your pack for the water it holds. 8: Clearly better than most.
HydraPak UK lists 102 g for 1 L: 102 g per litre, in the 100–179 g/L band (band 5 is under 100 g/L). Ultralight Outdoor Gear lists 101 g, which gives the same band.
Packed size (empty)
Estimate from maker's specs: soft bottle: rolls up when empty 8/10How much room it takes up when it is empty, for the water it holds. 8: Clearly better than most.
Estimate from maker's specs
In short
Good for
- Hikers who want a 1 L bottle that stands up on its own but rolls up when empty
- A bottle or dirty-water bag for a 42 mm threaded filter, such as the Katadyn BeFree or HydraPak's own 42 mm filter cap
- A second bottle for dry camps that takes little pack room when empty
Strengths
- 102 g for 1 L, about half the weight of a rigid 1 L bottle (HydraPak says it cuts weight by 50%)
- Stands upright like a hard bottle, so it is easy to fill and set down
- Twist-to-drink nozzle with a dust cover, and a bail handle for carrying or clipping to a pack
- 42 mm neck fits most 42 mm threaded filters (HydraPak lists its own filter cap and the Katadyn BeFree)
Weaknesses
- Twice the weight of the HydraPak Stow 1 L (51 g) for a similar rolled-up bottle
- No independent test of this version found, so ease of use and durability are estimates, not reviewed scores
- HydraPak gives no rolled-up size, so we cannot score packed size
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.