This is how the larger, Atlantic 260 sea kayak trolley from Eckla comes.
Two wheels and an aluminium frame which folds out. The sea kayak or canoe is strapped ontop.
It's too early to say whether it's any good. We used on in Greece this summer and it seemed to work OK on fairly rough roads.
I read so many reviews of different trolleys before buying I utterly confused myself.
[edit: The best, as usual, was by Douglas Wilcox - it's worth reading his helpful comment below. Clearly we still have a lot to learn about using a trolley.]
I went for this one because we'd used it in anger, and also because it's imported by System X, who're also agents for Werner Paddles.
The key thing I learnt when testing it today was to push the thing.
This is counter intuitive.
Instinctively, you want to pull the kayak and trolley behind you, but this gradually eases the strap further down the hull. S
ince the hull narrows, the strap becomes slacker and the trolley starts to twist.
By pushing the trolley, you keep the strap tight.
How this works in practice, only time will tell!