Isoflasche great, but the auto-lock breaks relatively easy ...

Possession of the Alfi Isoflasche since 2009 and am as far as the Isoleistung super happy.
Hot liquid holding min. 10 hrs. Long super hot and also have additional use hot or warm for a long time.

Advantage of the bottle:
> Good or very good insulation performance (5 years warranty on the bottle bzw.Isoleistung)
> Large opening for cleaning
> High-quality finish (bottle)
> Separable and absolutely tight automatic closure (easy cleaning)

Disadvantage:
>>> The automatic closure but is very vulnerable and was with me already the 2. x defective !!

1. closure has :-) kept 3 years, the 2nd barely nine months :-(
The problem here is m. E. after the brittle Plexiglas material from the closure of the plunger is, this breaks exactly at the thinnest point of the retaining ring is engaged for the spring. (Breaking point)
In my view, an absolute bad design or something that does not work in the long run :-(
Here Alfi should make improvements in any case and reconsider the design or the material used.

Although here are easy to get spare parts and cost not the world, it is still very angry at such a premium brand bottle.
Although an alternative, the execution be ordered with screw cap, but that is clearly impractical to use :-(

After complaining at Alfi, I will now get to grace a new automatic closure -> am curious :-))

If the part to be replaced as a goodwill gesture, it appears that it may well be worthwhile to purchase a branded ...

Addendum:
After about 1.5 weeks, unfortunately, is not yet the promised closure of Alfi replacement arrived as a goodwill gesture at me :-(

In the meantime, I have surveyed the defective component (Verschlusstößel), made a sketch and let make by a friend who works in the precision engineering of stainless steel, the new part is working perfectly and now survives sure the rest of the bottle :-)