These pictures are of Nature Nigh's Smart Dolly System sent to me by Mark Hammer. They turned up in my private email account rather than the onelessvan account.
It's a very versatile system with the possibility of a simple tool box on wheels as pictured on the right to a large cage system suitable for garden waste or whatever pictured left and centre. You choose the components you need. This, however, makes pricing out your trailer rather complex. Especially when all the prices are in US Dollars and some of the part's descriptions are in Swedish.
In it's basic toolbox form the trailer frame can carry 100Kg and the toolbox can take 50Kg / 70 Litres. This price for this base model is $289 including tax but excluding delivery. The unit is delivered disassembled with the wheels, towarm etc inside the box. Very neat. It's also possible to stack a second box ($23.20) on top of the first for a very useful 100Kg /140 Litre capacity. The trailer runs on 16 inch wheels made of plastic as standard though steel rims are available.