Osprey
Osprey Ultralight DrySack (20 L)
- Waterproof build: 5/10 How well its build keeps water out, from the published seams, closure and submersion claim.
- Weight for its size: 9/10 How much it adds to your pack for the space it protects.
Lowest price we found
£15.99 at Ultralight Outdoor Gear
Go to Ultralight Outdoor Gear Compare 4 shopsA cheap, light organiser or pack liner for a sleeping bag or clothes inside a rucksack
- Capacity
- 20 L
- Weight
- 62 g
- Seams
- Taped
- Closure
- Roll top
- Fabric
- 40 denier
Where to buy
Ultralight Outdoor Gear £15.99 In stock. Free delivery. Free UK delivery over £15.
View at shop: Ultralight Outdoor GearAlpinetrek £17.56 In stock. Free UK delivery from £85; the cost below that wasn't shown.
View at shop: AlpinetrekGO Outdoors £22 In stock. Delivery £3.99. Standard delivery £3.99, free over £80. Member-only prices are not included.
View at shop: GO OutdoorsOsprey £22 In stock. Delivery £6. Tundra Green is out of stock; Black, Waterfront Blue and Mars Orange are in stock. Free delivery over £75.
View at shop: OspreyPrices 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
Waterproof build
Estimate from maker's specs: seams, closure and water rating 5/10How well its build keeps water out, from the published seams, closure and submersion claim. 5: Does the job. Average for wild-camping gear.
Estimate from maker's specs
Weight for its size
From maker's figures 9/10How much it adds to your pack for the space it protects. 9: Among the best you can buy for this.
62 g for 20 L is 3.1 g/L, under 4.0 g/L. Osprey gives no weight (its page lists size and fabric only), so this is a shop and test figure: Ultralight Outdoor Gear lists 62 g, OutdoorGearLab 62.4 g and Alpinetrek 60 g, all under 4.0 g/L.
In short
Good for
- A cheap, light organiser or pack liner for a sleeping bag or clothes inside a rucksack
- Rain protection on UK hill trips when kept inside the pack
- Not for river crossings, packrafting or anything that may go under water
Strengths
- 62 g for 20 L (3.1 g/L)
- Rectangular shape stacks neatly in a pack
- 100% recycled 40D high-tenacity nylon with a roll-top closure
- Five sizes from 3 to 35 L
Weaknesses
- IPX5 means rain and splash proof, not submersible
- Osprey says its seams are waterproof-coated, not taped (UK shops say taped), so the waterproof build is an estimate, not a reviewed score
- Only OutdoorGearLab tested it, so durability and ease scores are missing
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.