You can see the difference in size between the steel type kett and the Kross. The black steel Kett seems dwarfed by the bigger Kross.
New in 2016 although not updated in the catalog is a new tandem part designed for the single hole mount.
There is a design flaw with this however. If you remove the kett at the back and leave the tandem piece on it will very quickly strip the teeth on your rear cassette. Hase asked the dealer to replace it.
Here is the first item that has been adapted for the trike. I have used the single strap supplied by Hase for folding the trike and put it through the hole in the tandem coupling. This stops it rubbing against the rear cassette. Perfect.
The gears look shiny and work very well.
Had a great ride out with my partner eating crisps whilst I pedal away.