Fellkit

Montane

Montane SoftFlask 360 mL Soft Flask

  • Weight for its size: 10/10 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

£15.99 at Ultralight Outdoor Gear

In stock. Free delivery. Checked 8 Nov 2026.

RRP £16, checked 20 Oct 2026.

Go to Ultralight Outdoor Gear Compare 2 shops

Short hill days where a small flask in a pack strap or hip pocket is enough

Type
Soft
Capacity
0.36 L
Weight
20 g
Packed
Not published

Where to buy

Ultralight Outdoor Gear £15.99 In stock. Free delivery. It lists 35 g where Montane lists 20 g.

View at shop: Ultralight Outdoor Gear

Montane £16 In stock. Montane's own shop. Its banner and delivery page disagree on the free-delivery rule, so check the shop for the delivery cost.

View at shop: Montane

Prices 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 10/10

How much it adds to your pack for the water it holds. 10: The best you can buy for this.

Montane lists 20 g for 360 mL: 56 g per litre, under 100 g/L. Ultralight Outdoor Gear lists 35 g (97 g per litre), which bands the same.

Packed size (empty)

Estimate from maker's specs: soft bottle: rolls up when empty 8/10

How 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

  • Short hill days where a small flask in a pack strap or hip pocket is enough
  • A light spare 360 mL for fastpacking or a trail-running vest
  • Drinking on the move: soft silicone bite valve for a high flow rate (Montane)

Strengths

  • 20 g for 360 mL: 56 g per litre
  • Compresses as you drink, so water does not slosh (Montane)
  • Wide screw-top opening for filling and cleaning, and for powders or gels
  • Tapered shape and base made for small pockets
  • Top-rack dishwasher safe, and BPA and PVC free (Montane)

Weaknesses

  • Montane lists 20 g, Ultralight Outdoor Gear 35 g
  • Montane gives no rolled-up size, so we cannot score packed size
  • No independent test found, so ease of use and durability are estimates, not reviewed scores

Sources

We haven't tested this ourselves. Every score comes from these specs, tests and reviews.

ShowHide sources (2)
  1. Montane: SoftFlask 360ml (spec page) Specs, 20 Oct 2026. Used for: weight for its size
  2. Craig Williams Ultra (YouTube): The Best (& Worst) Collapsible Water Bottles For Running! (13 flasks tested in belt and vests; Montane SoftFlask 360 scored 60 out of 100) Video, 1 Mar 2022