Retention hours only compare when the stated conditions match · review
A 500 ml double-walled stainless flask that publishes its capacity and nothing else the category is compared on: no retention hours, no steel grade, no mouth, no weight.
The bottom line The flask that publishes a capacity and stops. Everything the hub compares on is left blank, and that is worth knowing before it is compared with anything.
A 500 ml stainless steel flask with a stated double-walled construction and a lid the maker calls leak-proof, offered in several sizes and colours.
Six of the nine flasks in this hub quote retention in hours. This one quotes none. It says drinks stay ice-cold for hours and that coffee stays hot, and it stops there.
That matters less than it looks, because none of the nine publishes the conditions behind its hours either. But a flask with no figure cannot be put on the same line as one with a figure, however loosely that figure was arrived at.
No steel grade. 18/8 is named by four flasks here. This one says stainless steel.
No mouth diameter. Nothing tells you whether a bottle brush or an ice cube goes in.
No base diameter, no empty weight. The listing mentions running, cycling, camping and hiking; it does not say what the flask weighs before it is filled.
If the hours matter to you, this is not the listing to compare on. If 500 ml of double-walled steel with a leak-proof lid is the whole requirement, the listing does settle that much.
Selling between 9 € and 11 € across the German, French, Italian and Spanish Amazon stores when this page was checked.
It also sells on the American and British Amazon stores in the local currency, which the range above does not cover — that range counts euro stores and nothing else.
Every figure in this section is what Keepa returned on the day this page was last updated. Prices and offers change without notice.
Prices quoted in this text were read on 6 September 2026. The live price is at the top of the page.
| Capacity | 500 ml — stated in the title |
|---|---|
| Wall construction | Double-walled insulation — stated; the listing does not use the word vacuum |
| Steel grade | Not published on the listing — the flask is called 100% stainless steel, with no grade named |
| Hot retention | Not published on the listing — the listing says drinks are held hot or cold, with no number of hours |
| Cold retention | Not published on the listing — drinks are stated to stay ice-cold "for hours", which is not a figure |
| Retention conditions stated | Not published on the listing — no retention figure is published, so there are no conditions behind one |
| Mouth diameter | Not published on the listing |
| Lid type | Not published on the listing — a secure leak-proof lid is claimed, and its mechanism is not named |
| Seal availability | Not published on the listing |
| Base diameter | Not published on the listing |
| Finish | Not published on the listing — several sizes and colours are offered, and no coating is named |
| Empty weight | Not published on the listing |
| Amazon reference | B0CYSTYSHH (same reference on 6 Amazon marketplaces) |
| EAN | 3701152106301 |
The listing does not say. It claims drinks stay ice-cold for hours and that coffee stays hot, and it gives no number against either. Every comparison in this hub starts from a published figure, and this flask does not offer one.
That is a question about your route rather than about the flask, and the maker publishes nothing else to weigh it against — no empty weight, no mouth diameter for refilling from a wide source. The capacity is the only figure on the page.
500 ml · vacuum insulated · SUS 201 outside and SUS 304 inside · 24 h cold and 12 h hot stated · brushed finish · top handle
The only flask here that names a different steel for the inside and the outside, alongside a stated vacuum, both retention figures and a brushed finish.
Best for: A day out where a named inner steel, a stated vacuum and a dishwasher-safe body matter more than the hours quoted.
≈ 13 €
1 litre · 18/08 stainless · 13 h temperature stability stated, hot and cold not separated · bottle brush, jute bag and carabiner supplied
A 1 litre flask supplied with a natural-bristle brush and a carabiner, whose single retention figure of 13 hours is never split into hot and cold.
Best for: A litre bottle bought with its brush and its carry loop, where cleaning matters more than a comparable hours figure.
≈ $33 / £24 / 29 €
18/8 stainless · double wall · 24 h cold and 12 h hot stated · three lids supplied · powder coat · capacity not published
The flask with three lids in the box and both retention figures on the page — and no capacity anywhere in the listing, which is an unusual thing to leave out.
Best for: A walker who wants a straw lid on the trail and a plain lid at work, from one flask.
≈ £10 / 11 €
