Bought this as we were in a difficult place with a stubborn blockage. Imagine 30 years of accumulated dirt and soap scum in a thin 40mm tube and you have an idea...
The hose itself is quite handy, especially when it comes to mounting on the Kärcher. There was also quite a lot of dirt from the tube, that's where the positive ends. Almost immediately the head became jammed, and when pulling it back it turned out that the (seemingly useless?) plastic cover of the spray head was already coming loose. This then constantly hooked everything behind, so suddenly removed it completely. Don't really get the point of that thing since it just did its job without it.
Although we only got the hose 3 to 4 meters into the drain pipe, it turned out that there were several kinks in the hose. So it is either too rigid or not rigid enough. We didn't notice much of that "kink protection" from the description.
In addition, it only sprays backwards, but not forwards. As a result, you are limited in what kind of blockages you can solve. Our constipation has improved, but not completely resolved. My dad has a 20 year old alternative to a different type of pressure washer that sprays both forwards and backwards, and that really gets you through anything.
All in all, not super satisfied, especially since this hose cost half as much as the K2 high-pressure cleaner itself... Unfortunately, after 1x use, it is already so damaged that returning it is not an option.