Corroventa CTR 300 is the only one i find.
TTR300 seems to be found from a coupple of different manufacturers, but not the same as corroventa.
Do you have the names confused?
English is no problem in s Swedish forum, most people understands English.
But, often english posts tends to be spam messages.
As the corroventa is the more expensive product, with a bit higher capacity, one would think it is a better product, but i really dont know.
In general, you get what you pay for.
With this said, i know Acetec are produced in Älvsbyn, a small Swedish town in the north, where the costs are low, it might be good value for the money.